High-frequency power circulation circuit and control method
By designing high-frequency power cycle circuits and control methods, using positive and negative half-cycle working cycles and capacitor parallel drives, the problems of small number of devices and unbalanced temperature rise in the existing technology are solved, and a comprehensive and balanced assessment of semiconductor devices is achieved , improves the accuracy and coverage of the test.
Patent Information
- Application Number
- CN202411678374.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-01-03
AI Technical Summary
The existing power cycle test circuit has a small number of devices for a single assessment, which cannot simulate the actual system operating conditions, and the temperature rise is uneven, resulting in poor accuracy and comprehensiveness of the test results and insufficient coverage.
Design a high-frequency power cycle circuit, including eight semiconductor devices and inductors, simulate the switching timing characteristics of the AC system through positive and negative half-cycle working cycles, independently control the on-time of the switch tube, ensure that the device is balanced and heated, and store energy through capacitors. Drive the axle arm in parallel to achieve balanced assessment of all devices.
It realizes a comprehensive and balanced assessment of the long-term operating characteristics of semiconductor devices at high temperatures and high frequencies, improves the accuracy and comprehensiveness of power cycle tests, and ensures the reliability evaluation of the device under operating conditions.
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Figure CN119247091A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the semiconductor field, and in particular to a high-frequency power circulation circuit and a control method. Background Art
[0002] The power cycle test simulates the junction temperature fluctuation process of the device in actual application by turning on and off the external load current, and exposes the weak points of the device package in advance through a certain degree of accelerated aging. It has always been considered by the industry and academia as the most effective way to assess the reliability of power device packaging, and is also the most important means to establish device life models and life assessment.
[0003] The power test method is mainly power cycling (PC), which applies electrical stress and thermal stress to the device to assess the creep thermal fatigue characteristics of the device bonding point, chip solder layer, substrate solder layer and other packaging structures. The power cycle types are divided into long-cycle power cycles and short-cycle power cycles. Typical device failures and degradation in short-cycle power cycles are bond point detachment, solder layer delamination or excessive detachment, gate failure, busbar solder point detachment; long cycles are manifested as solder layer delamination or excessive detachment, packaging structure degradation, etc.
[0004] For example, Chinese patent document CN 117590188 A discloses a high-frequency power cycle circuit and control method, which includes: four power device switches, an inductor and an energy storage capacitor, a first switch tube and a fourth switch tube form a first switch bridge group, a second switch tube and a third switch tube form a second switch bridge group, a source of the first switch tube is connected to a drain of the third switch tube, a source of the second switch tube is connected to a drain of the fourth switch tube, a source of the first switch tube is connected in series with the inductor and then connected to the drain of the fourth switch tube, a source of the second switch tube is connected in series with the inductor and then connected to the drain of the third switch tube, and the control method controls the four power device switches through the timing of a driving signal to realize a soft switching state or a hard switching state of the device, and thereby realizes power cycling in the soft switching state or the hard switching state, but the implementation case provided in the patent document has a small number of devices tested at a time, and the temperature rise is uneven, and there is a risk that the temperature rise of individual devices is too high and the heating is serious. At the same time, the power cycle frequency of other traditional power cycle tests is low, and the working conditions cannot be simulated, so that the test results are incomplete and the coverage is poor. Summary of the invention
[0005] The current power cycle test circuit has a small number of devices tested at a single time, which cannot simulate the operating conditions in the actual system loop, and the temperature rise is uneven. Some devices in the test circuit have high temperature rise and serious heat generation, which reduces the accuracy and comprehensiveness of the test results and has poor coverage.
[0006] To solve the above problems, the purpose of the embodiment of the present application is to provide a high-frequency power circulation circuit, eight power semiconductor devices and an inductor, the eight semiconductor devices respectively constitute a first bridge arm and a second bridge arm, the first bridge arm is composed of a first switch tube and a first diode in parallel and a second switch tube and a second diode in parallel, the second bridge arm is composed of a third switch tube and a third diode in parallel and a fourth switch tube and a fourth diode in parallel, the emitter of the first switch tube is connected to the collector of the second switch tube, the emitter of the third switch tube is connected to the collector of the fourth switch tube, the emitter of the first switch tube, the inductor and the collector of the fourth switch tube are connected in series, the emitter of the third switch tube, the inductor and the collector of the second switch tube are connected in series, and the inductor current has two directions.
[0007] An embodiment of the present application also includes a control method, which includes the above-mentioned high-frequency power circulation circuit.
[0008] The purpose of the embodiments of the present application is to provide a high-frequency power cycle circuit and control method, which can simulate the switching timing characteristics in the AC system and design positive and negative half-cycle working cycles. Eight semiconductor power devices can be tested at the same time, and the conduction time of the switch tube can be independently controlled to adjust the working time and power consumption and heat generation of each device, so as to achieve the effect of balanced heat generation of all devices. The characteristic changes of semiconductor devices after long-term operation under high temperature and high frequency can be comprehensively and balancedly tested, thereby ensuring the accuracy and comprehensiveness of the power cycle test on the wafer.
[0009] In some embodiments, a capacitor is also included, which stores energy as a power source and is connected in parallel with the first bridge arm and the second bridge arm. The collector of the first switch tube and the collector of the third switch tube are connected to one end of the capacitor, and the emitter of the second switch tube and the emitter of the fourth switch tube are connected to the other end of the capacitor.
[0010] In some embodiments, when the current in the inductor is from left to right, it is in the positive direction, and this stage is a positive half-cycle cycle with a duration of 10ms;
[0011] When the current in the inductor is from right to left, it is in the negative direction. This stage is a negative half-cycle cycle with a duration of 10ms.
[0012] In some implementations, by controlling the on and off of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube, the circuit operates alternately between a positive half-cycle cycle and a negative half-cycle cycle.
[0013] In some implementations, the switching states of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube are respectively controlled by a driving signal.
[0014] In some implementations, before the timing of the driving signal, it is determined whether the circuit needs to enter a positive half-cycle cycle. If the determination result is no, the circuit enters a negative half-cycle cycle.
[0015] In some implementations, if the result of the determination is that a positive half-cycle cycle has been entered, the following steps are performed:
[0016] S1: Control the first switch tube and the fourth switch tube to be turned on to charge the inductor, and the positive current rises linearly;
[0017] S2: Keep the first switch on, control the fourth switch to be off, and the inductor to continue current flow, and the positive current remains unchanged;
[0018] S3: Control the first switch tube to turn off, the inductor discharges, and the positive current decreases linearly;
[0019] S4: The fourth switch tube is controlled to be turned on, the inductor continues to flow, and the positive current remains unchanged. At this time, a positive half cycle is completed.
[0020] In some embodiments, when the circuit is in a positive half-cycle cycle state, steps S1 to S4 correspond to moments t0 to t3 respectively, and moment t4 is set as the end time point of step S4. The first switch tube, the fourth switch tube, the second diode, and the third diode participate in the assessment, and the temperature rise of the first switch tube, the fourth switch tube, the second diode, and the third diode is controlled by adjusting the time length between the five time points t0 to t4.
[0021] In some embodiments, after the circuit completes a positive half cycle, it is determined whether the positive half cycle cycle is completed;
[0022] If the answer is no, then enter the positive half cycle S1 step;
[0023] If the answer is yes, a determination is made as to whether to enter the negative half cycle loop.
[0024] In some implementations, if the result of determining whether to enter a negative half-cycle cycle is yes, the circuit enters a negative half-cycle cycle; if the result is no, the circuit ends.
[0025] In some implementations, if the result of the determination is to enter a negative half-cycle, the following steps are performed:
[0026] S5: Control the second switch tube and the third switch tube to be turned on to charge the inductor, and the negative current decreases linearly;
[0027] S6: Keep the second switch tube turned on, control the third switch tube to turn off, the inductor continues to flow, and the negative current remains unchanged;
[0028] S7: Control the second switch tube to turn off, the inductor is discharged, and the negative current rises linearly;
[0029] S8: Control the three-switch tube to turn on, the inductor continues to flow, and the negative current remains unchanged. At this time, a negative half cycle is completed.
[0030] In some embodiments, when the circuit is in a negative half-cycle cycle state, steps S5 to S8 correspond to moments t0 to t3 respectively, and moment t4 is set as the end time point of step S8. The second switch tube, the third switch tube, the first diode, and the fourth diode participate in the assessment, and the temperature rise of the second switch tube, the third switch tube, the first diode, and the fourth diode is controlled by adjusting the time length between the five time points t0 to t4.
[0031] In some embodiments, after the circuit completes a negative half cycle, it is determined whether the negative half cycle cycle is completed;
[0032] If the answer is no, then enter the negative half cycle S5 step;
[0033] If the answer is yes, a determination is made as to whether to enter the positive half cycle.
[0034] In some implementations, if the result of determining whether to enter a positive half-cycle cycle is yes, the circuit enters a positive half-cycle; if the result is no, the circuit ends.
[0035] In some embodiments, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all insulated gate bipolar transistors, and the first diode, the second diode, the third diode and the fourth diode are all fast recovery epitaxial diodes. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.
[0037] Figure 1 This is a circuit structure diagram during a positive half cycle provided by some embodiments of the present application;
[0038] Figure 2 This is a circuit structure diagram during a negative half cycle provided by some embodiments of the present application;
[0039] Figure 3 is a control logic diagram of a high-frequency power cycle circuit provided by some embodiments of the present application;
[0040] Figure 4 is a schematic diagram of a full-cycle current waveform provided by some embodiments of the present application;
[0041] Figure 5 is a positive half-cycle timing diagram provided by some embodiments of the present application;
[0042] Figure 6 This is a negative half-cycle timing diagram provided by some embodiments of the present application.
[0043] Explanation of the accompanying drawings: 1. first switch tube; 2. first diode; 3. second switch tube; 4. second diode; 5. third switch tube; 6. third diode; 7. fourth switch tube; 8. fourth diode; 9. inductor; 10. capacitor. DETAILED DESCRIPTION
[0044] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in each embodiment of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not constitute any limitation, and the various embodiments can be combined with each other and referenced to each other without contradiction.
[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.
[0046] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.
[0047] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0048] Reference Figures 1 to 6 , the embodiments of the present application provide the following technical solutions:
[0049] like Figure 1 and Figure 2 As shown, the emitter of the first switch tube 1 and the collector of the second switch tube 3 are connected in series, the first switch tube 1 and the first diode 2 are connected in parallel, the second switch tube 3 and the second diode 4 are connected in parallel, the first switch tube 1 and the first diode 2 connected in parallel and the second switch tube 3 and the second diode 4 connected in parallel are connected in series to form a first bridge arm, the emitter of the third switch tube 5 and the collector of the fourth switch tube 7 are connected in series, the third switch tube 5 and the third diode 6 are connected in parallel, the fourth switch tube 7 and the fourth diode 8 are connected in parallel, and the third switch tube 5 and the third diode 6 connected in parallel and the fourth switch tube 7 and the fourth diode 8 connected in parallel form a second bridge arm;
[0050] The emitter of the first switch tube 1, the inductor 9 and the collector of the fourth switch tube 7 are connected in series, and the inductor 9 is also connected in series with the emitter of the third switch tube 5 and the collector of the second switch tube 3;
[0051] The capacitor 10 stores energy as a power source and is connected in parallel with the first bridge arm and the second bridge arm. The collector of the first switch tube 1 and the collector of the third switch tube 5 are connected to one end of the capacitor 10, and the emitter of the second switch tube 3 and the emitter of the fourth switch tube 7 are connected to the other end of the capacitor 10. By controlling the first switch tube 1, the second switch tube 3, the third switch tube 5 and the fourth switch tube 7 respectively, the inductor 9 generates current in two directions.
[0052] like Figure 3 As shown, a control method for a high-frequency power circulation circuit adopts the above-mentioned high-power circulation circuit, and sets that when the current in the inductor 9 is from left to right, it is in the positive direction, and this stage is a positive half-cycle cycle; when the current in the inductor 9 is from right to left, it is in the negative direction, and this stage is a negative half-cycle cycle. The first switch tube 1, the second switch tube 3, the third switch tube 5 and the fourth switch tube 7 are turned on and off by controlling the driving signal, so that the circuit operates alternately between the positive half-cycle cycle and the negative half-cycle cycle.
[0053] It should be noted that: before the timing of the driving signal, it is determined whether the circuit needs to enter the positive half-cycle cycle. If the determination result is no, it enters the negative half-cycle cycle;
[0054] If the judgment result is to enter the positive half cycle, perform the following steps:
[0055] S1: Control the first switch tube 1 and the fourth switch tube 7 to be turned on to charge the inductor 9;
[0056] S2: Maintain the first switch tube 1 on, control the fourth switch tube 7 to be off, and allow the inductor 9 to freewheel;
[0057] S3: Control the first switch tube 1 to turn off, and the inductor 9 discharges;
[0058] S4: the fourth switch tube 7 is controlled to be turned on, and the inductor 9 performs freewheeling, and a positive half cycle is completed at this time.
[0059] It should be noted that: after the circuit completes a positive half cycle, it determines whether the positive half cycle cycle is completed;
[0060] If the answer is no, then enter the positive half cycle S1 step;
[0061] If the answer is yes, a determination is made as to whether to enter the negative half cycle loop.
[0062] It should be noted that: if the result of determining whether to enter the negative half-cycle cycle is yes, the circuit enters the negative half-cycle cycle;
[0063] If the result is no, then end.
[0064] It should be noted that: if the judgment result is to enter the negative half-cycle cycle, the following steps are performed:
[0065] S5: Control the second switch tube 3 and the third switch tube 5 to be turned on to charge the inductor 9;
[0066] S6: Keep the second switch tube 3 turned on, control the third switch tube 5 to turn off, and the inductor 9 to carry out freewheeling;
[0067] S7: Control the second switch tube 3 to turn off, and the inductor 9 discharges;
[0068] S8: Control the three-switch tube 5 to be turned on, and the inductor 9 to continue current, and a negative half cycle is completed at this time.
[0069] It should be noted that: after the circuit completes a negative half cycle, it is determined whether the negative half cycle cycle is completed;
[0070] If the answer is no, then enter the negative half cycle S5 step;
[0071] If the answer is yes, a determination is made as to whether to enter the positive half cycle.
[0072] It should be noted that: if the result of determining whether to enter the positive half-cycle cycle is yes, the circuit enters the positive half-cycle;
[0073] If the result is no, then end.
[0074] It should be noted that: before the timing of the driving signal, it is determined whether the circuit needs to enter the positive half-cycle cycle. If the determination result is no, it enters the negative half-cycle cycle;
[0075] If the judgment result is to enter the negative half-cycle cycle, perform the following steps:
[0076] S5: Control the second switch tube 3 and the third switch tube 5 to be turned on to charge the inductor 9;
[0077] S6: Keep the second switch tube 3 turned on, control the third switch tube 3 to turn off, and the inductor 9 performs freewheeling;
[0078] S7: Control the second switch tube 3 to turn off, and the inductor 9 discharges;
[0079] S8: Control the three-switch tube 5 to be turned on, and the inductor 9 to continue current, and a negative half cycle is completed at this time.
[0080] It should be noted that: after the circuit completes a negative half cycle, it is determined whether the negative half cycle cycle is completed;
[0081] If the answer is no, then enter the negative half cycle S5 step;
[0082] If the answer is yes, a determination is made as to whether to enter the positive half cycle.
[0083] It should be noted that: if the result of determining whether to enter the positive half-cycle cycle is yes, the circuit enters the positive half-cycle;
[0084] If the result is no, then end.
[0085] It should be noted that: if the judgment result is to enter the positive half-cycle cycle, the following steps are performed:
[0086] S1: Control the first switch tube 1 and the fourth switch tube 7 to be turned on to charge the inductor 9;
[0087] S2: Maintain the first switch tube 1 on, control the fourth switch tube 7 to be off, and allow the inductor 9 to freewheel;
[0088] S3: Control the first switch tube 1 to turn off, and the inductor 9 discharges;
[0089] S4: the fourth switch tube 7 is controlled to be turned on, and the inductor 9 performs freewheeling, and a positive half cycle is completed at this time.
[0090] It should be noted that: after the circuit completes a positive half cycle, it determines whether the positive half cycle cycle is completed;
[0091] If the answer is no, then enter the positive half cycle S1 step;
[0092] If the answer is yes, a determination is made as to whether to enter the negative half cycle loop.
[0093] It should be noted that: if the result of determining whether to enter the negative half-cycle cycle is yes, the circuit enters the negative half-cycle cycle;
[0094] If the result is no, then end.
[0095] It should be noted that the power frequency cycle tg consists of a positive half cycle tp and a negative half cycle tn, and the current waveform of the inductor 9 is as follows: Figure 4 shown.
[0096] It should be noted that: Figure 5 As shown, when the circuit is in the positive half cycle state, steps S1 to S4 correspond to Figure 5 From the time t0 to t3 in the step, set the time t4 as the end time point of step S4;
[0097] At time t0, the first switch tube 1 and the fourth switch tube 7 are turned on at the same time, the capacitor 10 charges the inductor 9 through the first switch tube 1 and the fourth switch tube 7, and the positive current rises linearly;
[0098] At time t1, the fourth switch tube 7 is turned off, the third switch tube 5 is turned on, the first switch tube 1 remains on, the inductor 9 continues current through the third diode 6 and the first switch tube 1, and the positive current remains unchanged;
[0099] At time t2, the first switch tube 1 is turned off, the second switch tube 3 is turned on, and the third switch tube 5 remains on. The inductor 9 charges the capacitor 10 through the third diode 6 and the second diode 4, and the positive current decreases linearly.
[0100] At time t3, the third switch tube 5 is turned off, the fourth switch tube 7 is turned on, the second switch tube 3 remains on, the inductor 9 continues to flow through the second diode 4 and the fourth switch tube 7, and the positive current remains unchanged; at this time, the power cycle system completes a switching cycle cycle in the positive half cycle, and the subsequent system follows Figure 3 The process shown performs a positive half-cycle cycle until the cycle ends and then enters a negative half-cycle cycle or the cycle ends.
[0101] The first switch tube 1, the fourth switch tube 7, the second diode 4 and the third diode 6 participate in the assessment. By adjusting the time length between the five time points t0 to t4 to control the temperature rise of the first switch tube 1, the fourth switch tube 7, the second diode 4 and the third diode 6, the first switch tube 1, the fourth switch tube 7, the second diode 4 and the third diode 6 can be heated evenly.
[0102] It should be noted that: Figure 6 As shown, when the circuit is in the negative half cycle state, steps S5 to S8 correspond to Figure 6 From the time t0 to t3 in the step, set the time t4 as the end time point of step S8;
[0103] At time t0, the second switch tube 3 and the third switch tube 5 are turned on at the same time, the capacitor 10 charges the inductor 9 through the second switch tube 3 and the third switch tube 5, and the negative current decreases linearly;
[0104] At time t1, the third switch tube 5 is turned off, the fourth switch tube 7 is turned on, the second switch tube 3 remains on, the inductor 9 continues current through the fourth diode 8 and the second switch tube 3, and the negative current remains unchanged;
[0105] At time t2, the second switch tube 3 is turned off, the first switch tube 1 is turned on, the fourth switch tube 7 remains on, the inductor 9 charges the capacitor 10 through the fourth diode 8 and the first diode 2, and the negative current rises linearly;
[0106] At time t3, the fourth switch tube 7 is turned off, the third switch tube 5 is turned on, the first switch tube 1 remains on, the inductor 9 continues to flow through the first diode 2 and the third switch tube 5, and the negative current remains unchanged; at this time, the power cycle system completes a switching cycle cycle in the negative half cycle, and the subsequent system follows Figure 3 The process shown repeats the negative half cycle until the cycle ends or the positive half cycle begins.
[0107] The second switch tube 3, the third switch tube 5, the first diode 2 and the fourth diode 8 participate in the assessment. By adjusting the time length between the five time points t0 to t4 to control the temperature rise of the second switch tube 3, the third switch tube 5, the first diode 2 and the fourth diode 8, the second switch tube 3, the third switch tube 5, the first diode 2 and the fourth diode 8 can be heated evenly.
[0108] The high-frequency power cycle circuit and control method can design positive and negative half-cycle working cycles by simulating the switching timing characteristics in the AC system, and control the current direction in the inductor 9 by controlling the switching states of the first switch tube 1, the second switch tube 3, the third switch tube 5 and the fourth switch tube 7 to determine whether the circuit is in the positive half-cycle or the negative half-cycle. The first switch tube 1, the first diode 2, the second switch tube 3, the second diode 4, the third switch tube 5, the third diode 6, the fourth switch tube 7 and the fourth diode 8 can be tested at the same time, and the conduction time of the switch tube can be independently controlled by the above-mentioned control method to adjust the working time and power consumption and heat generation of each device, so as to achieve the effect of balanced heat generation of all devices, and the characteristic changes of semiconductor devices after long-term operation under high temperature and high frequency can be comprehensively and balancedly tested, so as to ensure the accuracy and comprehensiveness of the power cycle test on the wafer.
[0109] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.
Claims
1. A high frequency power circulation circuit, characterized in that: include: Eight power semiconductor devices and an inductor, the eight semiconductor devices respectively form a first bridge arm and a second bridge arm, the first bridge arm is composed of a first switch tube and a first diode connected in parallel and a second switch tube and a second diode connected in parallel, the second bridge arm is composed of a third switch tube and a third diode connected in parallel and a fourth switch tube and a fourth diode connected in parallel, the emitter of the first switch tube is connected to the collector of the second switch tube, the emitter of the third switch tube is connected to the collector of the fourth switch tube, the emitter of the first switch tube, the inductor and the collector of the fourth switch tube are connected in series, the emitter of the third switch tube, the inductor and the collector of the second switch tube are connected in series, and the inductor current has two directions.
2. A high frequency power circulation circuit according to claim 1, characterized in that: It also includes a capacitor, which stores energy as a power source and is connected in parallel with the first bridge arm and the second bridge arm. The collector of the first switch tube and the collector of the third switch tube are connected to one end of the capacitor, and the emitter of the second switch tube and the emitter of the fourth switch tube are connected to the other end of the capacitor.
3. A high frequency power circulation circuit according to claim 2, characterized in that: When the current in the inductor is from left to right, it is in the positive direction. This stage is a positive half-cycle cycle with a duration of 10ms. When the current in the inductor is from right to left, it is in a negative direction. This stage is a negative half-cycle cycle with a duration of 10ms.
4. A high frequency power circulation circuit according to claim 3, characterized in that: By controlling the on and off of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube, the circuit operates alternately between the positive half-cycle cycle and the negative half-cycle cycle.
5. A control method for a high-frequency power circulation circuit, using the high-frequency power circulation circuit according to claim 4, characterized in that: The switching states of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube are controlled by a driving signal.
6. The control method of a high-frequency power circulation circuit according to claim 5, characterized in that: Before the timing of the driving signal, it is determined whether the circuit needs to enter the positive half-cycle cycle. If the determination result is no, it enters the negative half-cycle cycle.
7. The control method of a high-frequency power circulation circuit according to claim 6, characterized in that: If the judgment result is to enter the positive half cycle, perform the following steps: S1: Control the first switch tube and the fourth switch tube to be turned on to charge the inductor, and the positive current rises linearly; S2: Maintain the first switch tube on, control the fourth switch tube to be off, and the inductor to freewheel, and the positive current remains unchanged; S3: controlling the first switch tube to turn off, the inductor is discharged, and the positive current decreases linearly; S4: Control the fourth switch tube to be turned on, the inductor performs freewheeling, and the positive current remains unchanged, and a positive half cycle is completed at this time.
8. The control method of a high-frequency power circulation circuit according to claim 7, characterized in that: When the circuit is in the positive half-cycle cycle state, steps S1 to S4 correspond to moments t0 to t3 respectively, and moment t4 is set as the end time point of step S4. The first switch tube, the fourth switch tube, the second diode and the third diode participate in the assessment, and the temperature rise of the first switch tube, the fourth switch tube, the second diode and the third diode is controlled by adjusting the time length between the five time points t0 to t4.
9. The control method of a high-frequency power circulation circuit according to claim 8, characterized in that: After the circuit completes a positive half cycle, it determines whether the positive half cycle cycle is completed; If the answer is no, then enter the positive half cycle S1 step; If the answer is yes, a determination is made as to whether to enter the negative half cycle loop.
10. The control method of a high-frequency power circulation circuit according to claim 9, characterized in that: If the result of determining whether to enter the negative half-cycle cycle is yes, the circuit enters the negative half-cycle cycle; If the result is no, then end.
11. The control method of a high-frequency power circulation circuit according to claim 10, characterized in that: If the judgment result is to enter the negative half-cycle cycle, perform the following steps: S5: Control the second switch tube and the third switch tube to be turned on to charge the inductor, and the negative current decreases linearly; S6: Maintain the second switch tube on, control the third switch tube to be off, the inductor performs freewheeling, and the negative current remains unchanged; S7: controlling the second switch tube to turn off, the inductor is discharged, and the negative current increases linearly; S8: Control the three-switch tube to be turned on, the inductor performs freewheeling, and the negative current remains unchanged, and a negative half cycle is completed at this time.
12. The control method of a high-frequency power circulation circuit according to claim 11, characterized in that: When the circuit is in the negative half-cycle cycle state, steps S5 to S8 correspond to moments t0 to t3 respectively, and moment t4 is set as the end time point of step S8. The second switch tube, the third switch tube, the first diode and the fourth diode participate in the assessment, and the temperature rise of the second switch tube, the third switch tube, the first diode and the fourth diode is controlled by adjusting the time length between the five time points t0 to t4.
13. The control method of a high-frequency power circulation circuit according to claim 12, characterized in that: After the circuit completes a negative half cycle, it determines whether the negative half cycle cycle is completed; If the answer is no, then enter the negative half cycle S5 step; If the answer is yes, a determination is made as to whether to enter the positive half cycle.
14. The control method of a high-frequency power circulation circuit according to claim 13, characterized in that: If the result of determining whether to enter the positive half cycle is yes, the circuit enters the positive half cycle; If the result is no, then end.
15. The control method of a high-frequency power circulation circuit according to claim 14, characterized in that: The first switch tube, the second switch tube, the third switch tube and the fourth switch tube are all insulated gate bipolar transistors, and the first diode, the second diode, the third diode and the fourth diode are all fast recovery epitaxial diodes.