Detection device and suppression method for direct-current output high-frequency ripples

Abstract

The invention relates to a switching power supply ripple detection technology, aims to solve the problems that an existing detection device is low in sampling precision and detection precision, poor in output ripple stability and the like, and provides a detection device and a suppression method for direct-current output high-frequency ripples, and the detection device comprises a device mounting plate, a positive conductive strip and a negative conductive strip. Two ends of the device mounting plate are respectively a direct-current input end and a direct-current output end; the positive and negative conductive strips are fixed on the device mounting plate and are connected with positive and negative electrodes of the direct-current input end; a filter capacitor, a common-mode balance magnetic ring, an output capacitor and a sampling detection device are sequentially connected in parallel between the direct-current input end and the direct-current output end of the device mounting plate, and a resistor-capacitor damping unit is connected in parallel between the sampling detection device and the direct-current output end and used for absorbing high-frequency resonance; positive and negative electrodes of the direct current output end are respectively connected with a plurality of capacitors for reducing common-mode noise; the detection device can effectively reduce the effective value and the peak-to-peak value of high-frequency ripples and improve the sampling precision and the detection precision.

Description

Technical Field

[0001] The invention relates to a detection technology for switching power supply ripple, and in particular to a detection device and a suppression method for direct current output high-frequency ripple. Background Art

[0002] In existing switching power supply equipment, when high voltage and large current are switched at a faster rate of change, electromagnetic radiation and switching ripple will be generated inside the power supply equipment, and electrostatic coupling between the power electronic switching device and the output circuit or the ground will generate common-mode noise, thereby affecting the sampling accuracy of the control sensor.

[0003] The current treatment measures for high-frequency ripple of the switching power supply are mainly to use filter capacitors and common-mode magnetic rings at both ends of the output detection device for filtering. The filter capacitor is used to process the high-frequency switching ripple generated in the power supply, and the common-mode magnetic ring is used to process the interference of the external environment of the switching power supply on the switching power supply. The structure of this method is relatively simple and can improve the detection accuracy of the detection device to a certain extent. However, since the common-mode voltage inside the switching power supply cannot be processed, and there will be parasitic inductance on the path between the filter capacitor and the detection device, the parasitic inductance will produce higher-frequency oscillations with the output filter capacitor, thereby affecting the sampling accuracy and output ripple, and it is difficult to meet the needs of higher sampling accuracy and high-stability output ripple. Therefore, it is imperative to seek a detection device that can suppress the high-frequency ripple of the switching power supply and improve the sampling accuracy and output ripple of the control sensor. Summary of the invention

[0004] The present invention aims to solve the problems of low sampling accuracy and detection accuracy of the existing switching power supply high-frequency ripple detection device, poor output ripple stability, etc., and proposes a DC output high-frequency ripple detection device and a suppression method.

[0005] To achieve the above purpose, the technical solution proposed by the present invention is:

[0006] A detection device for high-frequency ripple of direct current output, comprising a device mounting plate and positive and negative conductive strips, wherein two ends of the device mounting plate are respectively a direct current input end and a direct current output end, and the positive and negative conductive strips are fixed on the device mounting plate and connected to positive and negative electrodes of the direct current input end; a filter capacitor, a common-mode balancing magnetic ring, an output capacitor and a sampling detection device are sequentially connected between the direct current input end and the direct current output end of the device mounting plate, wherein the direct current input end is used to connect a switching power supply to be tested, and the direct current output end is used to connect an external load;

[0007] Its special features are:

[0008] A resistor and capacitor damping unit is connected in parallel between the positive and negative electrodes of the DC output terminal after the output capacitor to absorb high-frequency resonance;

[0009] A plurality of capacitors are respectively connected between the positive and negative electrodes of the DC output end and the ground to reduce common mode noise.

[0010] The filter capacitor is set at the DC input end to suppress the high-frequency switching sub-differential mode voltage ripple generated by the switching power supply equipment; the common-mode balancing magnetic ring is set at the rear end of the filter capacitor to suppress the common-mode noise interference between the output circuits and reduce the peak-to-peak value of the output voltage ripple.

[0011] Further, the resistor and capacitor damping unit includes a resistor and capacitor mounting plate fixedly connected to the device mounting plate, and an RC absorption circuit arranged on the resistor and capacitor mounting plate, the RC absorption circuit is used to absorb high-frequency resonance generated by high-frequency ripple during long-distance transmission;

[0012] The RC absorption circuit is connected in parallel to the positive and negative electrodes of the DC output terminal, and a grounding connection line is also provided between the RC absorption circuit and the device mounting plate.

[0013] Furthermore, one end of the capacitor is fixed to the device mounting plate through an output end insulator, and the other end is connected to the positive or negative electrode of the DC output end through a bent conductive strip;

[0014] The capacitor is used to provide a return path for the common-mode noise generated by the electrostatic coupling between the output circuit and the ground, thereby further reducing the common-mode noise. At the same time, it can handle the interference of the external environment on the power supply detection device, reduce the high-frequency ripple component, and improve the detection accuracy of the detection device. After experimental testing, this method has a more obvious effect on the insulation suspension installation design of the power module structure.

[0015] Furthermore, there are four capacitors, which are evenly distributed in pairs on both sides of the resistor and capacitor mounting plate and are correspondingly connected to the positive and negative electrodes of the DC output terminal.

[0016] Furthermore, the input ends of the positive and negative conductive strips are respectively fixed to the DC input ends of the device mounting plate through input end insulators.

[0017] The middle parts of the positive and negative conductive strips are respectively tightly fixed to the corresponding electrodes of the filter capacitor, and the output ends of the positive and negative conductive strips are connected to the common-mode balancing magnetic ring.

[0018] Furthermore, the filter capacitor is fixed on the device mounting plate through a filter capacitor mounting plate.

[0019] Furthermore, the common-mode balancing magnetic ring is fixed on the device mounting plate through a common-mode balancing magnetic ring mounting frame.

[0020] Furthermore, the output capacitor is a secondary filtering film absorption capacitor, which is used to absorb and suppress the high-frequency ripple output by the positive and negative electrodes, and absorb and suppress the high-frequency ripple noise around the sampling and detection device.

[0021] Furthermore, the sampling and detection device includes a detection mounting plate fixed on the device mounting plate, a first sampler and a second sampler arranged on the detection mounting plate, and the sampling and detection device is fixed on the device mounting plate through the detection mounting plate, the first sampler is arranged on the positive electrode, and the second sampler is arranged on the negative electrode.

[0022] At the same time, the present invention also proposes a method for suppressing high-frequency ripple of DC output, which adopts the above-mentioned detection device of high-frequency ripple of DC output, and is characterized in that it includes the following steps:

[0023] S1, connect the output end of the switching power supply to the positive and negative conductive strips on the device mounting plate, and the switching power supply generates high-frequency ripple;

[0024] S2, the high-frequency ripple generated by the switching power supply is filtered for the first time through the filter capacitor connected to the positive and negative conductive strips;

[0025] S3, the common-mode balanced magnetic ring connected to the rear end of the filter capacitor is used to suppress the common-mode noise between the output circuits for the first time, so as to reduce the peak value of the output voltage ripple;

[0026] S4, the high-frequency ripple generated by the switching power supply is filtered for the second time through the output capacitor;

[0027] S5, absorbs the ultra-high frequency oscillation generated at both ends of the output capacitor after secondary filtering through the resistor and capacitor damping unit;

[0028] S6. The capacitor at the DC output end can suppress the conduction and radiation noise of the switching power supply and reduce the peak-to-peak value of the ripple to achieve the suppression of the high-frequency ripple of the DC output.

[0029] Beneficial effects of the present invention:

[0030] [1] The detection device for high-frequency ripple in DC output of the present invention can effectively reduce the effective value and peak-to-peak value of the high-frequency ripple, improve the sampling accuracy of the detection device, and thus improve the electrical performance of the entire device.

[0031] [2] The input ends of the positive and negative conductive strips of the present invention are fixed on the device mounting plate through input insulators for structural support, and the middle part is fixed close to the electrode of the filter capacitor, which can effectively reduce the interference of the lead inductance, thereby improving the suppression effect of high-frequency ripple and improving the sampling accuracy of the detection device.

[0032] [3] The present invention arranges a plurality of capacitors between the DC output end of the detection device and the device mounting plate, so as to provide a return path for the common mode noise generated by the electrostatic coupling between the circuit at the DC output end and the ground, thereby further reducing the common mode noise; at the same time, it can also effectively deal with the interference of the external environment on the power supply detection device, reduce the high-frequency ripple component, and improve the detection accuracy of the detection device.

[0033] [4] In the present invention, a resistor and capacitor damping unit is connected in parallel between the sampling detection device and the DC output terminal, which can effectively absorb the high-frequency resonance formed during the long-distance transmission of the high-frequency switching ripple wave. It has a good absorption effect on the higher-frequency oscillation that is several times greater than the switching frequency of the power supply device generated during the transmission process, reduces the effective value of the high-frequency ripple, improves the sampling accuracy of the detection device and the overall electrical performance of the detection device, and has high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a circuit schematic diagram of a detection device for a DC output high-frequency ripple of the present invention;

[0035] Figure 2 It is a structural schematic diagram of a detection device for high-frequency ripple of direct current output according to the present invention;

[0036] Figure 3 It is a side view of the detection device of the DC output high frequency ripple of the present invention;

[0037] Figure 4 It is a flow chart of the method for suppressing high-frequency ripple of direct current output of the present invention;

[0038] Reference numerals:

[0039] 1-device mounting plate, 2-input end insulator, 3-positive and negative conductive strips, 4-filter capacitor, 5-filter capacitor mounting plate, 6-common mode balancing magnetic ring mounting frame, 7-resistor and capacitor mounting plate, 8-RC absorption circuit, 9-common mode balancing magnetic ring, 10-output capacitor, 11-sampling detection device, 1101-first sampler, 1102-second sampler; 12-detection mounting plate, 13-angle conductive strip, 14-output end insulator, 15-capacitor, 16-ground connection line. DETAILED DESCRIPTION

[0040] like Figures 1 to 3As shown, a detection device for high-frequency ripple of DC output includes: a device mounting plate 1, which is used to carry the overall structure of the detection device; the two ends of the device mounting plate 1 are respectively a DC input end and a DC output end, and a filter capacitor 4, a common-mode balancing magnetic ring 9, an output capacitor 10 and a sampling detection device 11 are sequentially connected in parallel between the DC input end and the DC output end of the device mounting plate 1, the DC input end is used to connect the switching power supply to be tested, and the DC output end is used to connect the external load; the output capacitor 10 in this embodiment adopts a secondary filter film absorption capacitor, and a resistor and capacitor damping unit is arranged after the output capacitor 10 to absorb high-frequency resonance;

[0041] The resistor and capacitor damping unit includes a resistor and capacitor mounting plate 7 fixedly connected to the device mounting plate 1, and an RC absorption circuit 8 arranged on the resistor and capacitor mounting plate 7. The RC absorption circuit 8 is used to absorb the high-frequency resonance generated by high-frequency ripple during long-distance transmission. It has a good absorption effect on higher-frequency oscillations that are several times greater than the switching frequency of the power supply equipment generated during the transmission process, reduces the effective value of the high-frequency ripple, improves the sampling accuracy of the detection device and the overall electrical performance of the detection device, and has high practicality.

[0042] The RC absorption circuit 8 is a plurality of resistors and capacitors connected in series. The RC absorption circuit 8 is connected in parallel to the positive and negative electrodes of the DC output terminal. A grounding line 16 is connected between the RC absorption circuit 8 and the device mounting plate 1 .

[0043] A filter capacitor 4 is installed on the positive and negative electrodes of the DC input end of the device mounting plate 1. The filter capacitor 4 is fixed on the device mounting plate 1 through the filter capacitor mounting plate 5, and is used to suppress the high-frequency switching sub-differential mode voltage ripple generated by the switching power supply device. The input end of the positive and negative conductive strips 3 is structurally supported and fixed on the device mounting plate 1 by the input end insulator 2, and is connected to the positive and negative electrodes of the DC input end. The middle of the positive and negative conductive strips 3 is tightly fixed to the corresponding electrodes of the filter capacitor 4, and the output end of the positive and negative conductive strips 3 is connected to the common mode balance magnetic ring 9, so as to reduce the interference of the lead inductance, achieve a better high-frequency ripple suppression effect, and improve the sampling accuracy of the detection device.

[0044] Secondly, the rear end of the filter capacitor 4 is connected to a common-mode balancing magnetic ring 9, which is fixed to the device mounting plate 1 through a common-mode balancing magnetic ring mounting frame 6 to suppress common-mode noise interference between output circuits and reduce the peak-to-peak value of the output voltage ripple.

[0045] The detection device for high-frequency ripple of DC output sets a secondary filter film absorption capacitor between the common-mode balanced magnetic ring 9 of the DC output and the sampling detection device 11, and uses the parasitic inductance of the positive and negative conductive strips 3 themselves and the filter capacitor 4 at the DC input end to form a CLC passive π-type filter, which further absorbs and suppresses the high-frequency ripple output by the positive and negative electrodes at the DC input end, and absorbs and suppresses the high-frequency ripple noise near the sampling detection device 11. The sampling detection device 11 includes a detection mounting plate 12 fixed on the device mounting plate 1, a first sampler 1101 and a second sampler 1102 arranged on the detection mounting plate 12, the first sampler 1101 is arranged on the positive electrode, and the second sampler 1102 is arranged on the negative electrode.

[0046] The high-frequency switching ripple is transmitted over a long distance through the parasitic inductance of the positive and negative conductive strips 3 and the secondary filter film absorption capacitor 10 to form a resonance, generating a higher-frequency oscillation that is several times the switching frequency of the power supply device. A CxRx resistor and capacitor damping unit is set at both ends of the secondary filter film absorption capacitor 10 to absorb the high-frequency resonance.

[0047] Four absorption capacitors 15 are arranged between the positive and negative electrodes of the DC output terminal and the ground. They are evenly distributed on both sides of the resistor and capacitor mounting plate 7 and are connected to the positive and negative electrodes of the DC output terminal to provide a return path for the common mode noise generated by the electrostatic coupling between the output circuit and the ground. One end of the capacitor 15 is fixed to the device mounting plate 1 through the output end insulator 14, and the other end is connected to the positive or negative electrode of the DC output terminal through the bent conductive strip 13, which can further reduce the common mode noise; at the same time, it can handle the interference of the external environment on the power supply detection device, reduce the high-frequency ripple component, and improve the detection accuracy of the detection device. According to experimental tests, this method is particularly effective for the insulated suspension installation design of the power module structure.

[0048] The DC output high-frequency ripple detection device in this embodiment can effectively reduce the effective value and peak-to-peak value of the high-frequency ripple, improve the sampling accuracy of the detection device, and thus improve the electrical performance of the entire device.

[0049] At the same time, the present invention also proposes a method for suppressing high-frequency ripple of DC output, such as Figure 4 As shown, the following steps are included:

[0050] S1, connecting the switching power supply to the positive and negative conductive strips 3 on the device mounting plate 1 through the DC input terminal, and the switching power supply generates high-frequency ripple;

[0051] S2, performing a first filtering on the high-frequency ripple generated by the switching power supply through the filter capacitor 4 connected to the positive and negative conductive strips 3;

[0052] S3, the common mode balance magnetic ring 9 connected to the rear end of the filter capacitor 4 is used to suppress the common mode noise between the output circuits for the first time, so as to reduce the peak value of the output voltage ripple;

[0053] S4, performing a second filtering on the high frequency ripple generated by the switching power supply through the output capacitor 10;

[0054] S5, absorbing the ultra-high frequency oscillation generated at both ends of the output capacitor 10 after secondary filtering through the resistor and capacitor damping unit;

[0055] S6. The capacitor 15 at the DC output end is used to suppress the conduction and radiation noise of the switching power supply and reduce the peak-to-peak value of the ripple, so as to suppress the high-frequency ripple of the DC output.

Claims

1. A detection device for a DC output high-frequency ripple, comprising a device mounting plate (1) and positive and negative conductive strips (3), wherein the two ends of the device mounting plate (1) are a DC input end and a DC output end respectively, and the positive and negative conductive strips (3) are fixed on the device mounting plate (1) and connected to the positive and negative electrodes of the DC input end; a filter capacitor (4), a common-mode balancing magnetic ring (9), an output capacitor (10) and a sampling detection device (11) are sequentially connected between the DC input end and the DC output end of the device mounting plate (1), wherein the DC input end is used to connect a switching power supply to be tested, and the DC output end is used to connect an external load; Features: A resistor and capacitor damping unit is connected in parallel between the positive and negative electrodes of the DC output end after the output capacitor (10) to absorb high-frequency resonance; A plurality of capacitors (15) are respectively connected between the positive and negative electrodes of the DC output end and the ground to reduce common mode noise.

2. The device for detecting high-frequency ripple of direct current output according to claim 1, characterized in that: The resistor and capacitor damping unit comprises a resistor and capacitor mounting plate (7) fixedly connected to the device mounting plate (1), and an RC absorption circuit (8) arranged on the resistor and capacitor mounting plate (7), wherein the RC absorption circuit (8) is used to absorb high-frequency resonance generated by high-frequency ripple during long-distance transmission; The RC absorption circuit (8) is connected in parallel to the positive and negative electrodes of the DC output end, and a grounding connection line (16) is also provided between the RC absorption circuit (8) and the device mounting plate (1).

3. The device for detecting high-frequency ripple of direct current output according to claim 2, characterized in that: One end of the capacitor (15) is fixed on the device mounting plate (1) via an output end insulator (14), and the other end is connected to the positive electrode or negative electrode of the DC output end via a bent angle conductive strip (13).

4. A device for detecting a DC output high frequency ripple according to any one of claims 1 to 3, characterized in that: There are four capacitors (15), which are evenly distributed in pairs on both sides of the resistor and capacitor mounting plate (7) and are correspondingly connected to the positive and negative electrodes of the DC output end.

5. A device for detecting high-frequency ripple of direct current output according to claim 4, characterized in that: The input ends of the positive and negative conductive bars (3) are respectively fixed on the device mounting plate (1) via input end insulators (2); The middle parts of the positive and negative conductive strips (3) are respectively tightly fixed to corresponding electrodes of the filter capacitor (4), and the output ends of the positive and negative conductive strips (3) are connected to the common-mode balancing magnetic ring (9).

6. The device for detecting high-frequency ripple of direct current output according to claim 5, characterized in that: The filter capacitor (4) is fixed on the device mounting plate (1) via a filter capacitor mounting plate (5).

7. A device for detecting high-frequency ripple in direct current output according to claim 6, characterized in that: The common mode balancing magnetic ring (9) is fixed on the device mounting plate (1) via a common mode balancing magnetic ring mounting frame (6).

8. A device for detecting high-frequency ripple of direct current output according to claim 7, characterized in that: The output capacitor (10) is a secondary filtering thin film absorption capacitor, which is used to absorb and suppress high-frequency ripples output by the positive and negative electrodes, and absorb and suppress high-frequency ripple noise around the sampling detection device (11).

9. A device for detecting a DC output high frequency ripple according to claim 8, characterized in that: The sampling detection device (11) comprises a detection mounting plate (12) fixed on the device mounting plate (1), a first sampler (1101) and a second sampler (1102) arranged on the detection mounting plate (12); the sampling detection device is fixed to the device mounting plate (1) via the detection mounting plate (12); the first sampler (1101) is arranged on the positive electrode, and the second sampler (1102) is arranged on the negative electrode.

10. A method for suppressing high-frequency ripple of a direct current output, using the device for detecting high-frequency ripple of a direct current output according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, connecting the output end of the switching power supply to the positive and negative conductive strips (3) on the device mounting plate (1), so that the switching power supply generates high-frequency ripple; S2, performing a first filtering on the high-frequency ripple generated by the switching power supply through a filter capacitor (4) connected to the positive and negative conductive strips (3); S3, performing a first suppression of the common mode noise between the output circuits through the common mode balance magnetic ring (9) connected to the rear end of the filter capacitor (4), so as to reduce the peak value of the output voltage ripple; S4, performing a second filtering on the high frequency ripple generated by the switching power supply through the output capacitor (10); S5, absorbing the ultra-high frequency oscillation generated at both ends of the output capacitor (10) after secondary filtering through a resistor and capacitor damping unit; S6. The capacitor (15) at the DC output terminal is used to suppress the conduction and radiation noise of the switching power supply and reduce the peak-to-peak value of the ripple, so as to suppress the high-frequency ripple of the DC output.

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