CN114035008A - Voltage withstand test circuit and device - Google Patents
Voltage withstand test circuit and device Download PDFInfo
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- CN114035008A CN114035008A CN202111324410.8A CN202111324410A CN114035008A CN 114035008 A CN114035008 A CN 114035008A CN 202111324410 A CN202111324410 A CN 202111324410A CN 114035008 A CN114035008 A CN 114035008A
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Abstract
The invention belongs to the technical field of voltage withstanding tests and discloses a voltage withstanding test circuit and a voltage withstanding test device. The circuit comprises a rectifying module, a direct current withstand voltage testing module, an alternating current withstand voltage testing module and a coupling module; the rectification module rectifies the power supply voltage of the commercial power and outputs direct current voltage to the direct current withstand voltage test module and the alternating current withstand voltage test module; the direct-current voltage withstand test module carries out inversion voltage regulation, boosting and rectification processing on the direct-current voltage to obtain high-voltage direct-current voltage, and the high-voltage direct-current voltage is output to the coupling module; the alternating current withstand voltage testing module carries out inversion voltage regulation and boosting treatment on the direct current voltage to obtain high-voltage alternating current voltage which is output to the coupling module; the coupling module determines a target bias alternating voltage according to the high-voltage alternating voltage and the high-voltage direct voltage to realize the voltage withstanding test of the device to be tested. The target bias alternating-current voltage with the high-voltage direct-current bias is obtained through voltage coupling of the two groups of test modules, the real working state of the transformer is simulated, the working environment of a device to be tested is accurately restored, and the test precision is improved.
Description
Technical Field
The invention relates to the technical field of voltage withstanding tests, in particular to a voltage withstanding test circuit and a voltage withstanding test device.
Background
With the improvement of safety awareness of consumers and the increasing importance of manufacturers on product quality, manufacturers can test the safety performance of products in the product design and production processes to ensure the quality and safety of the products, and among various safety performance tests, a voltage withstanding test is the most basic and most common test means. According to different technical requirements of different electrical products, a test voltage higher than normal operation is applied to the product and the test is continuously carried out for a period of time, if the leakage current of the tested part is kept within a specified safety range within a specified time, the part can be judged to be very safe to operate under normal conditions, and the process is a withstand voltage test.
The high-frequency transformer has the advantages of high efficiency, power resource saving, longer service life than a common transformer, energy saving and environmental protection. However, when the voltage withstand test is performed on the power frequency transformer, the traditional voltage withstand test device is obtained by voltage regulation and pressurization of power frequency current, namely, the frequency of the obtained high-voltage alternating current is still 50Hz, and the requirement on the high-frequency alternating current in the voltage withstand test of the high-frequency transformer cannot be met.
The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.
Disclosure of Invention
The invention mainly aims to provide a voltage withstanding test circuit and a voltage withstanding test device, and aims to solve the technical problem that the existing voltage withstanding test device cannot meet the voltage withstanding test requirement of a high-frequency transformer.
In order to achieve the above object, the present invention provides a withstand voltage test circuit, including: the device comprises a rectification module, a direct current withstand voltage test module, an alternating current withstand voltage test module and a coupling module; the input end of the rectification module is connected with a mains supply, the output end of the rectification module is respectively connected with the input end of the direct current withstand voltage testing module and the input end of the alternating current withstand voltage testing module, the output end of the direct current withstand voltage testing module and the output end of the alternating current withstand voltage testing module are respectively connected with the input end of the coupling module, and the output end of the coupling module is connected with a device to be tested; wherein the content of the first and second substances,
the rectification module is used for receiving the power supply voltage of the commercial power, rectifying the power supply voltage and outputting direct-current voltage to the direct-current withstand voltage test module and the alternating-current withstand voltage test module;
the direct-current withstand voltage testing module is used for carrying out inversion voltage regulation processing, boosting processing and rectification processing on the direct-current voltage so as to obtain high-voltage direct-current voltage and outputting the high-voltage direct-current voltage to the coupling module;
the alternating current withstand voltage testing module is used for carrying out inversion voltage regulation processing and boosting processing on the direct current voltage so as to obtain high-voltage alternating current voltage and outputting the high-voltage alternating current voltage to the coupling module;
the coupling module is used for determining a target bias alternating-current voltage according to the high-voltage alternating-current voltage and the high-voltage direct-current voltage so as to realize the withstand voltage test of the device to be tested through the target bias alternating-current voltage.
Optionally, the dc withstand voltage testing module includes a first full-bridge inverter unit, a first transformer unit, and a rectification output unit, which are connected in sequence; wherein the content of the first and second substances,
the first full-bridge inversion unit is used for performing inversion processing and phase-shifting voltage regulation processing on the direct-current voltage to obtain high-frequency square wave alternating-current voltage and outputting the high-frequency square wave alternating-current voltage to the first voltage transformation unit;
the first voltage transformation unit is used for boosting the high-frequency square wave alternating voltage to obtain a high-voltage alternating voltage and outputting the high-voltage alternating voltage to the rectification output unit;
the rectification output unit is used for rectifying the high-voltage alternating voltage to obtain high-voltage direct voltage and outputting the high-voltage direct voltage to the coupling module.
Optionally, the first full-bridge inverting unit includes: the MOS transistor comprises a first MOS transistor, a second MOS transistor, a third MOS transistor and a fourth MOS transistor; wherein the content of the first and second substances,
the source electrode of the first MOS tube is connected with the drain electrode of the second MOS tube, the drain electrode of the third MOS tube is connected with the drain electrode of the first MOS tube, the source electrode of the third MOS tube is connected with the drain electrode of the fourth MOS tube, and the source electrode of the fourth MOS tube is connected with the source electrode of the second MOS tube;
and the drain electrode of the first MOS tube and the source electrode of the second MOS tube are respectively connected with the output end of the rectifying module.
Optionally, the first voltage transformation unit includes: a first transformer; wherein the content of the first and second substances,
the first end of the primary winding of the first transformer is connected with the source electrode of the first MOS tube, the second end of the primary winding of the first transformer is connected with the drain electrode of the fourth MOS tube, and the secondary winding of the first transformer is connected with the input end of the rectification output unit.
Optionally, the rectification output unit includes: a rectifier diode and a first capacitor; wherein the content of the first and second substances,
the anode of the rectifier diode is connected with the first end of the secondary winding of the first transformer, the cathode of the rectifier diode is connected with the first end of the first capacitor, and the second end of the first capacitor is connected with the second end of the secondary winding of the first transformer.
Optionally, the alternating current withstand voltage testing module comprises a second full-bridge inverter unit and a second voltage transformation unit which are connected in sequence; wherein the content of the first and second substances,
the second full-bridge inversion unit is used for carrying out inversion voltage regulation processing on the direct-current voltage so as to obtain a high-frequency square wave alternating-current voltage and outputting the high-frequency square wave alternating-current voltage to the second voltage transformation unit;
the second voltage transformation unit is used for boosting the high-frequency square wave alternating voltage to obtain a high-voltage alternating voltage and outputting the high-voltage alternating voltage to the coupling module.
Optionally, the second full-bridge inverting unit includes: a fifth MOS tube, a sixth MOS tube, a seventh MOS tube and an eighth MOS tube; wherein the content of the first and second substances,
the source electrode of the fifth MOS tube is connected with the drain electrode of the sixth MOS tube, the drain electrode of the seventh MOS tube is connected with the drain electrode of the fifth MOS tube, the source electrode of the seventh MOS tube is connected with the drain electrode of the eighth MOS tube, and the source electrode of the eighth MOS tube is connected with the source electrode of the sixth MOS tube;
and the drain electrode of the fifth MOS tube and the source electrode of the sixth MOS tube are respectively connected with the output end of the rectification module.
Optionally, the second voltage transforming unit includes: a second transformer; wherein the content of the first and second substances,
the first end of the primary winding of the second transformer is connected with the source electrode of the fifth MOS tube, the second end of the primary winding of the second transformer is connected with the drain electrode of the eighth MOS tube, and the secondary winding of the second transformer is connected with the input end of the coupling module.
Optionally, the rectifier module comprises: the first switch, the second switch, the first diode, the second diode, the third diode, the fourth diode and the second capacitor; wherein the content of the first and second substances,
the first end of the first switch and the first end of the second switch are respectively connected with two ends of the mains supply;
the second end of the first switch is connected with the anode of the first diode, and the anode of the first diode is connected with the cathode of the second diode;
a second end of the second switch is connected with an anode of the third diode, an anode of the third diode is connected with a cathode of the fourth diode, a cathode of the first diode is connected with a cathode of the third diode, and an anode of the second diode is connected with an anode of the fourth diode;
the first end of the second capacitor is connected with the cathode of the third diode, and the second end of the second capacitor is connected with the anode of the fourth diode.
In addition, in order to achieve the above object, the present invention further provides a withstand voltage testing apparatus including the withstand voltage testing circuit as described above.
The embodiment provides a voltage withstanding test circuit, which comprises a rectifying module, a direct current voltage withstanding test module, an alternating current voltage withstanding test module and a coupling module. After the power supply voltage of the commercial power is rectified by the rectifying module, the direct current voltage is output to the direct current withstand voltage testing module and the alternating current withstand voltage testing module; the direct-current withstand voltage testing module carries out inversion voltage regulation processing, boosting processing and rectification processing on the direct-current voltage to obtain high-voltage direct-current voltage, and the high-voltage direct-current voltage is output to the coupling module; the alternating current withstand voltage testing module carries out inversion voltage regulation processing and boosting processing on the direct current voltage to obtain high-voltage alternating current voltage which is output to the coupling module; the coupling module determines a target bias alternating voltage according to the high-voltage alternating voltage and the high-voltage direct voltage to realize the voltage withstanding test of the device to be tested. The high-voltage high-frequency alternating current with high-voltage direct current bias, namely the target bias alternating current voltage, is obtained after voltage coupling output by the direct current voltage withstand test module and the alternating current voltage withstand test module, the target bias alternating current voltage can simulate the real working state of a device to be tested, the working environment of the device to be tested is restored more accurately, real and effective test data can be obtained, the test precision is improved, meanwhile, the test cost is reduced, the test efficiency is improved, the high-voltage high-frequency alternating current with high-voltage direct current bias can be used for simulating the voltage withstand working scene of a transformer under the real working condition, and the technical problem that the existing voltage withstand test device cannot meet the voltage withstand test requirement of the high-frequency transformer is solved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a block diagram of a voltage withstand test circuit according to an embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of a voltage withstanding test circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a full-bridge square wave inverter driving signal according to an embodiment of the voltage withstanding test circuit of the present invention;
FIG. 4 is a schematic diagram of each half bridge arm of a diode-uncontrolled full-bridge rectifier circuit according to an embodiment of the withstand voltage test circuit of the present invention;
FIG. 5 is a schematic circuit diagram of a DC insulation test source according to an embodiment of the invention;
FIG. 6 is a schematic circuit diagram of an AC insulation test source according to an embodiment of the invention;
fig. 7 is a schematic diagram of a high-voltage and high-frequency alternating current with a high-voltage direct-current bias after coupling according to an embodiment of the voltage withstand test circuit of the present invention.
The reference numbers illustrate:
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should be considered to be absent and not within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a block diagram of a voltage withstand test circuit according to an embodiment of the present invention. In an embodiment of the present invention, a withstand voltage test circuit includes: the device comprises a rectifying module 100, a direct current withstand voltage testing module 200, an alternating current withstand voltage testing module 300 and a coupling module 400; the input end of the rectifying module 100 is connected with a mains supply, the output end of the rectifying module 100 is respectively connected with the input end of the direct current withstand voltage testing module 200 and the input end of the alternating current withstand voltage testing module 300, the output end of the direct current withstand voltage testing module 200 and the output end of the alternating current withstand voltage testing module 300 are respectively connected with the input end of the coupling module 400, and the output end of the coupling module 400 is connected with a device to be tested; wherein the content of the first and second substances,
the rectifying module 100 is configured to receive a power supply voltage of the commercial power, rectify the power supply voltage, and output a dc voltage to the dc withstand voltage testing module 200 and the ac withstand voltage testing module 300. In this embodiment, the rectifying module 100 receives and rectifies a power voltage of a commercial power AC, where the commercial power AC may be a 220V commercial power, where the commercial power is a commercial power (industrial power) frequency, and the frequency of the commercial power is generally 50hz, and in this embodiment, the 220V commercial power refers to a 50hz alternating current.
Specifically, the rectifier module 100 may include a diode uncontrolled full-bridge rectifier circuit, and the 220V power frequency commercial power is rectified by the diode uncontrolled full-bridge rectifier circuit to output a dc voltage. The diode uncontrolled full bridge rectifier circuit is a rectifier circuit consisting of rectifier diodes without control function, when the input alternating current voltage is constant, the direct current voltage obtained on the load is a circuit which cannot be adjusted, and the alternating current voltage externally added with 220V power frequency commercial power can be changed into the direct current voltage by utilizing the unidirectional conductive performance of the rectifier diodes. For the ideal case, i.e. the rectifier diode has neither inertia nor loss, since the switching on and off of the diode takes only a few microseconds, the process of rectification can be regarded as instantaneous for a half cycle of 50Hz current of 220V mains. The rectifier module 100 may further include other types of rectifier circuits, which is not limited in this embodiment.
The dc withstand voltage test module 200 is configured to perform inversion voltage regulation processing, boosting processing, and rectification processing on the dc voltage to obtain a high-voltage dc voltage, and output the high-voltage dc voltage to the coupling module 400. In this embodiment, the dc withstand voltage testing module 200 may include a first full-bridge inverter unit, a first transforming unit, and a rectification output unit, wherein the first full-bridge inverter unit performs an inverter process and a phase-shifting and voltage-regulating process on the dc voltage to obtain a high-frequency square wave ac voltage, and outputs the high-frequency square wave ac voltage to the first transforming unit; the first voltage transformation unit is used for boosting the high-frequency square wave alternating voltage to obtain a high-voltage alternating voltage and outputting the high-voltage alternating voltage to the rectification output unit; the rectification output unit rectifies the high-voltage ac voltage to obtain a high-voltage dc voltage, and outputs the high-voltage dc voltage to the coupling module 400.
Specifically, the power frequency current of the 220V power frequency mains supply is rectified by a diode uncontrolled full-bridge rectifier circuit and then outputs a direct current voltage, the direct current withstand voltage test module 200 inverts, regulates and rectifies the direct current voltage to obtain a high-voltage direct current voltage, and the high-voltage direct current voltage can be used as a direct current insulation test source of a device to be tested, such as a transformer, and is used for withstand voltage test of the transformer.
The ac withstand voltage test module 300 is configured to perform inversion voltage regulation processing and boosting processing on the dc voltage to obtain a high-voltage ac voltage, and output the high-voltage ac voltage to the coupling module 400. In this embodiment, the ac withstand voltage testing module 300 may include a second full-bridge inverter unit and a second transformer unit; the second full-bridge inversion unit is used for carrying out inversion voltage regulation on the direct-current voltage to obtain a high-frequency square wave alternating-current voltage and outputting the high-frequency square wave alternating-current voltage to the second voltage transformation unit; the second voltage transforming unit boosts the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and outputs the high-voltage ac voltage to the coupling module 400.
Specifically, the power frequency current of the 220V power frequency mains supply is rectified by a diode uncontrolled full-bridge rectifier circuit and then outputs a direct current voltage, and the alternating current withstand voltage test module 300 inverts and regulates the direct current voltage to obtain a high-voltage alternating current voltage, wherein the high-voltage alternating current voltage can be a high-frequency square wave voltage, and is used as an alternating current insulation test source of a device to be tested, such as a transformer, and is used for withstand voltage test of the transformer.
The coupling module 400 is configured to determine a target bias ac voltage according to the high-voltage ac voltage and the high-voltage dc voltage, so as to implement a withstand voltage test of the device to be tested through the target bias ac voltage. In this embodiment, the high-frequency high-voltage alternating current output by the ac withstand voltage testing module 300 and the high-voltage direct current output by the dc withstand voltage testing module 200 may be independently adjusted as required, and the coupling module 400 is configured to determine a target bias alternating voltage according to the high-voltage alternating voltage and the high-voltage direct voltage, referring to fig. 7, where fig. 7 is a schematic diagram of a high-voltage high-frequency alternating current with a high-voltage direct current bias after coupling according to an embodiment of the withstand voltage testing circuit of the present invention. That is to say, the high-frequency high-voltage alternating current and the high-voltage direct current are connected in series and output to obtain the high-voltage high-frequency alternating current with the high-voltage direct current bias, namely the target bias alternating current voltage, the target bias alternating current voltage can simulate the real working state of the device to be tested, the working environment of the device to be tested is restored more accurately, real and effective test data can be obtained, the test precision is improved, meanwhile, the test cost is reduced, the test efficiency is improved, the high-voltage high-frequency alternating current with the high-voltage direct current bias can be used for simulating the voltage-withstanding working scene of the transformer under the real working condition, and the voltage-withstanding test of the power electronic transformer can be realized.
This embodiment proposes a withstand voltage test circuit, and this circuit includes: the device comprises a rectifying module 100, a direct current withstand voltage testing module 200, an alternating current withstand voltage testing module 300 and a coupling module 400; the input end of the rectifying module 100 is connected with a mains supply, the output end of the rectifying module 100 is respectively connected with the input end of the direct current withstand voltage testing module 200 and the input end of the alternating current withstand voltage testing module 300, the output end of the direct current withstand voltage testing module 200 and the output end of the alternating current withstand voltage testing module 300 are respectively connected with the input end of the coupling module 400, and the output end of the coupling module 400 is connected with a device to be tested; the rectifying module 100 is configured to receive a power supply voltage of the commercial power, rectify the power supply voltage, and output a dc voltage to the dc withstand voltage testing module 200 and the ac withstand voltage testing module 300; the dc withstand voltage test module 200 is configured to perform inversion phase shift voltage regulation, boosting, and rectification on the dc voltage to obtain a high-voltage dc voltage, and output the high-voltage dc voltage to the coupling module 400; the ac withstand voltage testing module 300 is configured to perform inversion voltage regulation processing and boosting processing on the dc voltage to obtain a high-voltage ac voltage, and output the high-voltage ac voltage to the coupling module 400; the coupling module 400 is configured to determine a target bias ac voltage according to the high-voltage ac voltage and the high-voltage dc voltage, so as to implement a withstand voltage test of the device to be tested through the target bias ac voltage. The high-voltage high-frequency alternating current with high-voltage direct current bias, namely the target bias alternating voltage, is obtained after the voltages output by the direct current voltage withstand test module 200 and the alternating current voltage withstand test module 300 are coupled, the target bias alternating voltage can simulate the real working state of a device to be tested, the working environment of the device to be tested can be restored more accurately, real and effective test data can be obtained, the test precision is improved, meanwhile, the test cost is reduced, the test efficiency is improved, the high-voltage high-frequency alternating current with high-voltage direct current bias can be used for simulating the voltage withstand working scene of the transformer under the real working condition, and the technical problem that the existing voltage withstand test device cannot meet the voltage withstand test requirement of the high-frequency transformer is solved.
Further, referring to fig. 2, the dc withstand voltage testing module 200 includes a first full-bridge inverter unit 201, a first transformer unit 202, and a rectification output unit 203, which are connected in sequence; wherein the content of the first and second substances,
the first full-bridge inverter unit 201 is configured to perform an inverter process and a phase-shifting voltage-regulating process on the dc voltage to obtain a high-frequency square-wave ac voltage, and output the high-frequency square-wave ac voltage to the first voltage transforming unit 202;
the first voltage transformation unit 202 is configured to perform voltage boosting processing on the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and output the high-voltage ac voltage to the rectification output unit 203;
the rectification output unit 203 is configured to rectify the high-voltage ac voltage to obtain a high-voltage dc voltage, and output the high-voltage dc voltage to the coupling module 400.
It should be noted that, the first full-bridge inverter unit 201 in the dc withstand voltage test module 200 performs an inverter voltage regulation process on the dc voltage to obtain a high-frequency square wave ac voltage. The first full-bridge inverter unit 201 may include a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, and a fourth MOS transistor Q4, wherein the first full-bridge inverter unit 201 may employ full-bridge square wave inversion, driving signals of an upper half bridge arm and a lower half bridge arm in the first full-bridge inverter unit 201 may be PWM signals with adjustable duty ratios and dead zones, driving signals of the first MOS transistor Q1 and the third MOS transistor Q3 at diagonal positions are kept consistent, and driving signals of the second MOS transistor Q2 and the fourth MOS transistor Q4 at diagonal positions are kept consistent, where the driving signals are shown in fig. 3.
It is easy to understand that the first transforming unit 202 in the dc withstand voltage testing module 200 performs a boosting process on the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and outputs the high-voltage ac voltage to the rectifying output unit 203. The first transforming unit 202 may include a first transformer T1, the first transformer T1 is a high-ratio transformer, and the step-up ratio of the high-ratio transformer may be flexibly designed according to the actually required output voltage level.
It should be understood that the rectification output unit 203 in the dc withstand voltage test module 200 rectifies the high-voltage ac voltage to obtain a high-voltage dc voltage, and outputs the high-voltage dc voltage to the coupling module 400. The rectification output unit 203 may include a rectification diode D and a first capacitor C1. The high-voltage ac voltage is converted into a high-voltage dc voltage through the rectifier diode D and the first capacitor C1, and the high-voltage dc voltage may be a high-voltage dc voltage of 0 to 35kV, which is not limited in the present embodiment.
Further, with continued reference to fig. 2, the first full-bridge inverting unit 201 includes: the MOS transistor comprises a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3 and a fourth MOS transistor Q4; wherein the content of the first and second substances,
the source of the first MOS transistor Q1 is connected to the drain of the second MOS transistor Q2, the drain of the third MOS transistor Q3 is connected to the drain of the first MOS transistor Q1, the source of the third MOS transistor Q3 is connected to the drain of the fourth MOS transistor Q4, and the source of the fourth MOS transistor Q4 is connected to the source of the second MOS transistor Q2;
the drain of the first MOS transistor Q1 and the source of the second MOS transistor Q2 are respectively connected to the output terminal of the rectifying module 100.
It should be noted that, the first full-bridge inverter unit 201 in the dc withstand voltage test module 200 performs an inverter process and a phase shift voltage regulation process on the dc voltage to obtain a high-frequency square wave ac voltage. The first full-bridge inverter unit 201 may employ full-bridge square wave inversion, the driving signals of the upper half bridge arm and the lower half bridge arm in the first full-bridge inverter unit 201 may be PWM signals with adjustable duty ratios and dead zones, the driving signals of the first MOS transistor Q1 and the third MOS transistor Q3 at diagonal positions are kept consistent, and the driving signals of the second MOS transistor Q2 and the fourth MOS transistor Q4 at diagonal positions are kept consistent, where the driving signals are shown in fig. 3.
In addition, the first full-bridge inverter unit 201 may further include other types of inverter circuits to convert the dc voltage into the high-frequency square-wave ac voltage, which is not limited in this embodiment.
Further, with continued reference to fig. 2, the first transforming unit 202 includes: a first transformer T1; wherein the content of the first and second substances,
a first end of a primary winding of the first transformer T1 is connected to the source of the first MOS transistor Q1, a second end of the primary winding of the first transformer T1 is connected to the drain of the fourth MOS transistor Q4, and a secondary winding of the first transformer T1 is connected to the input of the rectification output unit 203.
It should be noted that the first transforming unit 202 may include a first transformer T1, and the first transformer T1 may boost the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and output the high-voltage ac voltage to the rectifying output unit 203.
Specifically, the first transformer T1 is a high-ratio transformer, the step-up ratio of the high-ratio transformer can be flexibly designed according to the actually required output voltage level, and the first transformer T1 can be phase-shifted and voltage-regulated by the inversion of the first full-bridge inversion unit 201. In this embodiment, the transformation ratio of the first transformer T1 in the dc withstand voltage test is 1: 100.
further, with continued reference to fig. 2, the rectified output unit 203 includes: a rectifier diode D and a first capacitor C1; wherein the content of the first and second substances,
an anode of the rectifying diode D is connected to a first end of the secondary winding of the first transformer T1, a cathode of the rectifying diode D is connected to a first end of the first capacitor C1, and a second end of the first capacitor C1 is connected to a second end of the secondary winding of the first transformer T1.
It should be noted that the rectification output unit 203 may include a rectification diode D and a first capacitor C1, rectify the high-voltage ac voltage output by the first transformer T1 through the rectification diode D and the first capacitor C1 to obtain a high-voltage dc voltage, and output the high-voltage dc voltage to the coupling module 400. The rectification output unit 203 may include other types of rectification circuits to convert a high-voltage ac voltage into a high-voltage dc voltage. The high-voltage dc voltage output by the rectifying output unit 203 may be 0 to 35kV, which is not limited in this embodiment.
Specifically, the rectification output unit 203 may further include a diode-uncontrolled full-bridge rectification circuit, and each half bridge arm of the diode-uncontrolled full-bridge rectification circuit may be connected in series by using a plurality of silicon carbide (SiC) diodes with high withstand voltage levels according to voltage stress.
Specifically, the first capacitor C1 may be used for filtering, or a plurality of capacitors with high withstand voltage levels may be connected in series to withstand high withstand voltage for filtering.
Further, with reference to fig. 2, the ac withstand voltage testing module 300 includes a second full-bridge inverter unit 301 and a second transformer unit 302 connected in sequence; wherein the content of the first and second substances,
the second full-bridge inverter unit 301 is configured to perform inverter voltage regulation on the dc voltage to obtain a high-frequency square wave ac voltage, and output the high-frequency square wave ac voltage to the second voltage transformation unit 302;
the second voltage transforming unit 302 is configured to boost the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and output the high-voltage ac voltage to the coupling module 400.
It should be noted that the second full-bridge inverter unit 301 in the ac withstand voltage test module 300 performs an inverter voltage regulation process on the dc voltage to obtain a high-frequency square-wave ac voltage. The second full-bridge inverter unit 301 may include a fifth MOS transistor Q5, a sixth MOS transistor Q6, a seventh MOS transistor Q7, and an eighth MOS transistor Q8, where the second full-bridge inverter unit 301 may employ full-bridge square wave inversion, driving signals of an upper bridge arm and a lower bridge arm in the second full-bridge inverter unit 301 may be PWM signals with adjustable duty ratios and dead zones, driving signals of the fifth MOS transistor Q5 and the seventh MOS transistor Q7 at diagonal positions are kept consistent, and driving signals of the sixth MOS transistor Q6 and the eighth MOS transistor Q8 at diagonal positions are kept consistent.
It is easy to understand that the second transforming unit 302 in the ac withstand voltage testing module 300 performs a boosting process on the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and outputs the high-voltage ac voltage to the coupling module 400. The second transforming unit 302 may include a second transformer T2, the second transformer T2 is a high-ratio transformer, and the step-up ratio of the high-ratio transformer may be flexibly designed according to the actually required output voltage level.
Specifically, the ac withstand voltage testing module 300 converts the dc voltage into a high-voltage ac voltage, which may be a high-voltage ac voltage with a frequency of 20kHz and an amplitude of 0 to 30kV, which is not limited in this embodiment.
Further, with continued reference to fig. 2, the second full-bridge inverting unit 301 includes: a fifth MOS transistor Q5, a sixth MOS transistor Q6, a seventh MOS transistor Q7, and an eighth MOS transistor Q8; wherein the content of the first and second substances,
the source of the fifth MOS transistor Q5 is connected to the drain of the sixth MOS transistor Q6, the drain of the seventh MOS transistor Q7 is connected to the drain of the fifth MOS transistor Q5, the source of the seventh MOS transistor Q7 is connected to the drain of the eighth MOS transistor Q8, and the source of the eighth MOS transistor Q8 is connected to the source of the sixth MOS transistor Q6;
the drain of the fifth MOS transistor Q5 and the source of the sixth MOS transistor Q6 are respectively connected to the output terminal of the rectifier module 100.
It should be noted that the second full-bridge inverter unit 301 in the ac withstand voltage test module 300 performs an inverter voltage regulation process on the dc voltage to obtain a high-frequency square-wave ac voltage. The second full-bridge inverter unit 301 may employ full-bridge square wave inversion, the driving signals of the upper half bridge arm and the lower half bridge arm in the second full-bridge inverter unit 301 may be PWM signals with adjustable duty ratios and dead zones, the driving signals of the fifth MOS transistor Q5 and the seventh MOS transistor Q7 at diagonal positions are kept consistent, and the driving signals of the sixth MOS transistor Q6 and the eighth MOS transistor Q8 at diagonal positions are kept consistent.
In addition, the second full-bridge inverter unit 301 may further include other types of inverter voltage regulating circuits to convert the dc voltage into the high-frequency square wave ac voltage, which is not limited in this embodiment.
Further, with continued reference to fig. 2, the second transforming unit 302 includes: a second transformer T2; wherein the content of the first and second substances,
a first end of a primary winding of the second transformer T2 is connected to the source of the fifth MOS transistor Q5, a second end of the primary winding of the second transformer T2 is connected to the drain of the eighth MOS transistor Q8, and a secondary winding of the second transformer T2 is connected to the input terminal of the coupling module 400.
It should be noted that the second transforming unit 302 may include a second transformer T2, and the second transformer T2 boosts the high-frequency square wave ac voltage to obtain a high-voltage ac voltage, and outputs the high-voltage ac voltage to the coupling module 400.
Specifically, the second transformer T2 is a high-transformation-ratio transformer, the boosting ratio of the high-transformation-ratio transformer can be flexibly designed according to the output voltage level of the actual requirement, and the second transformer T2 can perform inversion phase-shifting and voltage regulation through the second full-bridge inversion unit 301, so that flexible voltage output within the required range is realized. In this embodiment, the transformation ratio of the second transformer T2 in the ac withstand voltage test is 1: 120.
further, with continued reference to fig. 2, the rectifier module 100 includes: a first switch S1, a second switch S2, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a second capacitor C2; wherein the content of the first and second substances,
a first terminal of the first switch S1 and a first terminal of the second switch S2 are connected to two ends of the commercial power respectively;
a second terminal of the first switch S1 is connected with an anode of the first diode D1, and an anode of the first diode D1 is connected with a cathode of the second diode D2;
a second terminal of the second switch S2 is connected to an anode of the third diode D3, an anode of the third diode D3 is connected to a cathode of the fourth diode D4, a cathode of the first diode D1 is connected to a cathode of the third diode D3, and an anode of the second diode D2 is connected to an anode of the fourth diode D4;
a first terminal of the second capacitor C2 is connected to the cathode of the third diode D3, and a second terminal of the second capacitor C2 is connected to the anode of the fourth diode D4.
It should be noted that, the rectification module 100 receives and rectifies a power supply voltage of a commercial power AC, where the commercial power AC may be a 220V commercial power, where the commercial power is a commercial power (industrial power) frequency, and the frequency of the commercial power is generally 50hz, and in this embodiment, the 220V commercial power refers to a 50hz alternating current. The rectification module 100 may include a first switch S1, a second switch S2, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a second capacitor C2.
Specifically, the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 may include a diode-uncontrolled full-bridge rectifier circuit, and the 220V power frequency mains supply is rectified by the diode-uncontrolled full-bridge rectifier circuit to output a dc voltage. The diode uncontrolled full bridge rectifier circuit is a rectifier circuit consisting of rectifier diodes without control function, when the input alternating current voltage is constant, the direct current voltage obtained on the load is a circuit which cannot be adjusted, and the alternating current voltage externally added with 220V power frequency commercial power can be changed into the direct current voltage by utilizing the unidirectional conductive performance of the rectifier diodes. For the ideal case, i.e. the rectifier diode has neither inertia nor loss, since the switching on and off of the diode takes only a few microseconds, the process of rectification can be regarded as instantaneous for a half cycle of 50Hz current of 220V mains. The rectifier module 100 may further include other types of rectifier circuits, which is not limited in this embodiment.
It is easy to understand that each half bridge arm of the diode-uncontrolled full-bridge rectification circuit can be connected in series by a plurality of silicon carbide (SiC) diodes with high voltage-resistant grade according to voltage stress, and the method is shown in fig. 4.
Specifically, the second capacitor C2 may be used for filtering, or a plurality of capacitors with high withstand voltage levels may be connected in series to withstand high withstand voltage for filtering.
In this embodiment, the high-frequency high-voltage ac and the high-voltage dc can be independently adjusted as required, and referring to fig. 5, the rectifier module 100 can be combined with the first full-bridge inverter unit 201, the first transformer unit 202, and the rectifier output unit 203 in the dc withstand voltage test module 200 to form a dc withstand voltage test source, which is used as a dc insulation test source for a transformer. Referring to fig. 6, the rectification module 100 may be combined with the second full-bridge inverter unit 301 and the second transforming unit 302 in the ac withstand voltage test module 300 as an ac withstand voltage test source for a transformer.
In order to achieve the above object, the present invention further provides a withstand voltage testing apparatus, which includes the withstand voltage testing circuit as described above. The specific structure of the voltage withstanding test circuit refers to the above embodiments, and since the voltage withstanding test apparatus adopts all technical solutions of all the above embodiments, all beneficial effects brought by the technical solutions of the above embodiments are at least achieved, and are not repeated here.
Further, it is to be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solution of the present invention or portions thereof that contribute to the prior art may be embodied in the form of a software product, where the computer software product is stored in a storage medium (e.g. Read Only Memory (ROM)/RAM, magnetic disk, optical disk), and includes several instructions for enabling a terminal device (e.g. a mobile phone, a computer, a server, or a network device) to execute the method according to the embodiments of the present invention.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. A withstand voltage test circuit, characterized by comprising: the device comprises a rectification module, a direct current withstand voltage test module, an alternating current withstand voltage test module and a coupling module; the input end of the rectification module is connected with a mains supply, the output end of the rectification module is respectively connected with the input end of the direct current withstand voltage testing module and the input end of the alternating current withstand voltage testing module, the output end of the direct current withstand voltage testing module and the output end of the alternating current withstand voltage testing module are respectively connected with the input end of the coupling module, and the output end of the coupling module is connected with a device to be tested; wherein the content of the first and second substances,
the rectification module is used for receiving the power supply voltage of the commercial power, rectifying the power supply voltage and outputting direct-current voltage to the direct-current withstand voltage test module and the alternating-current withstand voltage test module;
the direct-current withstand voltage testing module is used for carrying out inversion voltage regulation processing, boosting processing and rectification processing on the direct-current voltage so as to obtain high-voltage direct-current voltage and outputting the high-voltage direct-current voltage to the coupling module;
the alternating current withstand voltage testing module is used for carrying out inversion voltage regulation processing and boosting processing on the direct current voltage so as to obtain high-voltage alternating current voltage and outputting the high-voltage alternating current voltage to the coupling module;
the coupling module is used for determining a target bias alternating-current voltage according to the high-voltage alternating-current voltage and the high-voltage direct-current voltage so as to realize the withstand voltage test of the device to be tested through the target bias alternating-current voltage.
2. A voltage withstanding test circuit according to claim 1, wherein the dc voltage withstanding test module comprises a first full-bridge inverter voltage regulating unit, a first voltage transforming unit and a rectification output unit, which are connected in sequence; wherein the content of the first and second substances,
the first full-bridge inversion unit is used for performing inversion processing and phase-shifting voltage regulation processing on the direct-current voltage to obtain high-frequency square wave alternating-current voltage and outputting the high-frequency square wave alternating-current voltage to the first voltage transformation unit;
the first voltage transformation unit is used for boosting the high-frequency square wave alternating voltage to obtain a high-voltage alternating voltage and outputting the high-voltage alternating voltage to the rectification output unit;
the rectification output unit is used for rectifying the high-voltage alternating voltage to obtain high-voltage direct voltage and outputting the high-voltage direct voltage to the coupling module.
3. The withstand voltage test circuit of claim 2, wherein the first full-bridge inverter unit comprises: the MOS transistor comprises a first MOS transistor, a second MOS transistor, a third MOS transistor and a fourth MOS transistor; wherein the content of the first and second substances,
the source electrode of the first MOS tube is connected with the drain electrode of the second MOS tube, the drain electrode of the third MOS tube is connected with the drain electrode of the first MOS tube, the source electrode of the third MOS tube is connected with the drain electrode of the fourth MOS tube, and the source electrode of the fourth MOS tube is connected with the source electrode of the second MOS tube;
and the drain electrode of the first MOS tube and the source electrode of the second MOS tube are respectively connected with the output end of the rectifying module.
4. A withstand voltage test circuit according to claim 3, wherein said first transforming unit includes: a first transformer; wherein the content of the first and second substances,
the first end of the primary winding of the first transformer is connected with the source electrode of the first MOS tube, the second end of the primary winding of the first transformer is connected with the drain electrode of the fourth MOS tube, and the secondary winding of the first transformer is connected with the input end of the rectification output unit.
5. A withstand voltage test circuit according to claim 4, wherein the rectification output unit includes: a rectifier diode and a first capacitor; wherein the content of the first and second substances,
the anode of the rectifier diode is connected with the first end of the secondary winding of the first transformer, the cathode of the rectifier diode is connected with the first end of the first capacitor, and the second end of the first capacitor is connected with the second end of the secondary winding of the first transformer.
6. A voltage withstanding test circuit according to claim 1, wherein the ac voltage withstanding test module includes a second full-bridge inverter unit and a second transformer unit connected in sequence; wherein the content of the first and second substances,
the second full-bridge inversion unit is used for carrying out inversion voltage regulation processing on the direct-current voltage so as to obtain a high-frequency square wave alternating-current voltage and outputting the high-frequency square wave alternating-current voltage to the second voltage transformation unit;
the second voltage transformation unit is used for boosting the high-frequency square wave alternating voltage to obtain a high-voltage alternating voltage and outputting the high-voltage alternating voltage to the coupling module.
7. The withstand voltage test circuit of claim 6, wherein the second full-bridge inverter unit comprises: a fifth MOS tube, a sixth MOS tube, a seventh MOS tube and an eighth MOS tube; wherein the content of the first and second substances,
the source electrode of the fifth MOS tube is connected with the drain electrode of the sixth MOS tube, the drain electrode of the seventh MOS tube is connected with the drain electrode of the fifth MOS tube, the source electrode of the seventh MOS tube is connected with the drain electrode of the eighth MOS tube, and the source electrode of the eighth MOS tube is connected with the source electrode of the sixth MOS tube;
and the drain electrode of the fifth MOS tube and the source electrode of the sixth MOS tube are respectively connected with the output end of the rectification module.
8. The withstand voltage test circuit according to claim 7, wherein the second voltage transforming unit includes: a second transformer; wherein the content of the first and second substances,
the first end of the primary winding of the second transformer is connected with the source electrode of the fifth MOS tube, the second end of the primary winding of the second transformer is connected with the drain electrode of the eighth MOS tube, and the secondary winding of the second transformer is connected with the input end of the coupling module.
9. A withstand voltage test circuit according to any one of claims 1 to 8, wherein the rectifying module includes: the first switch, the second switch, the first diode, the second diode, the third diode, the fourth diode and the second capacitor; wherein the content of the first and second substances,
the first end of the first switch and the first end of the second switch are respectively connected with two ends of the mains supply;
the second end of the first switch is connected with the anode of the first diode, and the anode of the first diode is connected with the cathode of the second diode;
a second end of the second switch is connected with an anode of the third diode, an anode of the third diode is connected with a cathode of the fourth diode, a cathode of the first diode is connected with a cathode of the third diode, and an anode of the second diode is connected with an anode of the fourth diode;
the first end of the second capacitor is connected with the cathode of the third diode, and the second end of the second capacitor is connected with the anode of the fourth diode.
10. A withstand voltage testing apparatus characterized by comprising the withstand voltage testing circuit according to any one of claims 1 to 9.
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