Non-straight-through active auxiliary full-range soft switching inverter

Abstract

The invention discloses a non-straight-through active auxiliary full-range soft switching inverter which comprises a direct current voltage module, a power frequency voltage commutation parallel resonance energy storage capacitor bridge arm connected with the direct current voltage module and used for outputting power frequency alternating current square waves. The high-frequency SPWM modulation lag switch bridge arm is connected with the power frequency voltage commutation parallel resonance energy storage capacitor bridge arm and is used for carrying out SPWM modulation on the power frequency alternating current square wave voltage and outputting a high-frequency square wave; the filter network is connected with the power frequency voltage commutation parallel resonance energy storage capacitor bridge arm and the high-frequency SPWM modulation lag switch bridge arm and is used for filtering high-frequency square waves output by the high-frequency SPWM modulation lag switch bridge arm to obtain output voltage; and the high-frequency auxiliary switch and the junction capacitance energy storage and release network are connected with the direct-current voltage module and the high-frequency SPWM modulation lag switch bridge arm and are used for realizing soft switching of a high-frequency switching tube.

Description

Technical Field

[0001] The invention relates to the technical field of power generation and transformation, and in particular to a non-shoot-through active auxiliary full-range soft switch inverter. Background Art

[0002] With the rapid development of new energy grid-connected power generation, electric vehicles, and aerospace, inverters are being used more and more widely, and the requirements for high frequency and miniaturization of inverters are also increasing rapidly. However, miniaturizing the inverter using high-frequency switching will increase the loss. The above problems seriously hinder the improvement of the power density of the inverter. Exploring new topologies, increasing the switching frequency, and using soft switching technology are the main solutions. The soft switching solution can improve the power density and solve the problems of large switching losses and electromagnetic interference (EMI). Traditional full-bridge inverters have problems such as switch tube direct conduction and large switching losses, which reduce the stability and conversion efficiency of the inverter. Setting the dead time to avoid direct conduction of the bridge arm will constrain the high frequency of the inverter, which is not conducive to improving the power density of the inverter. Summary of the invention

[0003] Technical purpose: In view of the defects in the prior art, the present invention discloses a full-range soft-switching inverter with active auxiliary without direct-flow. The control mode is unipolar modulation. The full-range soft switching of all high-frequency switching tubes is realized by controlling the advance conduction time of the auxiliary switching tube, so as to achieve the goals of high efficiency, high power density and high reliability while ensuring the working reliability of the inverter.

[0004] Technical solution: In order to achieve the above technical objectives, the present invention adopts the following technical solution.

[0005] A non-shoot-through active auxiliary full-range soft switching inverter, comprising:

[0006] A DC voltage module, including a positive output terminal and a negative output terminal, for providing an input voltage for the inverter;

[0007] The power frequency voltage commutation parallel resonant energy storage capacitor bridge arm is connected to the DC voltage module and includes a power frequency switch bridge arm composed of two power frequency switch tubes; it is used to output a power frequency AC square wave in the case of a single power supply input;

[0008] The high-frequency SPWM modulation hysteresis switch bridge arm is connected to the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm, and includes a high-frequency switch bridge arm composed of two high-frequency switch tubes, and is used to perform SPWM modulation on the power frequency AC square wave voltage output by the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm, so as to output a high-frequency square wave after unipolar modulation;

[0009] A filter network is connected to the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm and the high frequency SPWM modulation hysteresis switch bridge arm, and is used for filtering the high frequency square wave output by the high frequency SPWM modulation hysteresis switch bridge arm to obtain an output voltage;

[0010] The high-frequency auxiliary switch and the junction capacitor energy storage and release network are connected to the DC voltage module and the high-frequency SPWM modulation hysteresis switch bridge arm to realize the soft switching of the high-frequency switch tube;.

[0011] Beneficial effects:

[0012] (1) The full-range soft-switching inverter control method proposed in the present invention has no dead time limitation, thereby improving the reliability of the inverter operation.

[0013] (2) The present invention provides hardware circuit conditions for soft-on and soft-off for all switches by controlling the advance conduction time of the third high-frequency switch tube S3 and the fourth high-frequency switch tube S4 of the auxiliary switch tube. The active auxiliary network circuit structure proposed by the present invention is simple, which is beneficial to improving the inverter efficiency and reducing the loss on the basis of ensuring the reliability of the inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A structural topology diagram of a non-shoot-through active auxiliary full-range soft-switching inverter according to an embodiment of the present invention;

[0015] Figure 2 A timing diagram of a drive signal, a switch tube voltage and current, a storage capacitor voltage, a resonant inductor current, a junction capacitor voltage, and a filter inductor current under SPWM advance conduction control of a non-shoot-through active auxiliary full-range soft-switching inverter according to an embodiment of the present invention;

[0016] Figures 3 to 10 It is a first-stage modal diagram of a full-range soft-switching inverter without shoot-through active auxiliary according to an embodiment of the present invention;

[0017] Figures 11 to 18 A second-stage modal diagram of a full-range soft-switching inverter without shoot-through active auxiliary according to an embodiment of the present invention;

[0018] Figures 19 to 26 The third stage modal diagram of a full-range soft-switching inverter without shoot-through active auxiliary according to an embodiment of the present invention;

[0019] Figures 27 to 34 This is a fourth-stage modal diagram of a full-range soft-switching inverter with active auxiliary without shoot-through according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] The present invention proposes a non-shoot-through active auxiliary full-range soft switching inverter, in which all high-frequency switch tubes do not need to set dead zones, and full-range soft switching is achieved by reducing the energy of the switch tube junction capacitance to zero before the switch tube is turned on each time, thereby reducing the switching loss of the switch tube, and on this basis, the active auxiliary switch control method is simple.

[0022] As attached Figure 1 As shown, a non-shoot-through active auxiliary full-range soft-switching inverter of this embodiment includes: a DC voltage module 1, a power frequency voltage commutated parallel resonant energy storage capacitor bridge arm 2, a filter network 3, a high-frequency SPWM modulation hysteresis switch bridge arm 4, a high-frequency auxiliary switch and junction capacitor energy storage and release network 5;

[0023] The DC voltage module 1 includes a positive output terminal and a negative output terminal, which are used to provide an input voltage U for the inverter. i ;

[0024] The power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2 is connected to the DC voltage module 1, and includes a power frequency switch bridge arm composed of two power frequency switch tubes; it is used to output a power frequency AC square wave under the condition of single power input, realize bipolar output, and junction capacitor energy storage and release direction change of the high frequency switch tube;

[0025] The power frequency voltage commutated parallel resonant energy storage capacitor bridge arm 2 includes a first power frequency switch tube Q1 and a second power frequency switch tube Q2. The drain of the first power frequency switch tube Q1 is connected to the positive output end of the DC voltage module 1, that is, the input voltage U i The positive electrode of the first power frequency switch tube Q1 is connected, the drain of the first power frequency switch tube Q1 serves as the first output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2, the source of the first power frequency switch tube Q1 is connected to the drain of the second power frequency switch tube Q2, the midpoint of the resonant energy storage capacitors C1 and C2 is connected to the drain of the third high frequency switch tube S3, and the source of the second power frequency switch tube Q2 is connected to the negative output end of the DC voltage module 1; the source of the second power frequency switch tube Q2 serves as the second output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2, and the first output end and the second output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2 output a power frequency AC square wave;

[0026] The high-frequency SPWM modulation hysteresis switch bridge arm 4 is connected to the power-frequency voltage-commutated parallel resonant energy storage capacitor bridge arm 2, and includes a high-frequency switch bridge arm composed of two high-frequency switch tubes, which is used to perform SPWM modulation on the power-frequency AC square wave voltage output by the power-frequency voltage-commutated parallel resonant energy storage capacitor bridge arm 2, so as to output a high-frequency square wave after unipolar modulation; the switch tube of the high-frequency SPWM modulation hysteresis switch bridge arm lags behind the switch tube of the high-frequency auxiliary switch and the junction capacitor energy storage and release network, wherein the first high-frequency switch tube S1 lags behind the third high-frequency switch tube S3 in conducting; the second high-frequency switch tube S2 lags behind the fourth high-frequency switch tube S4 in conducting;

[0027] The high-frequency SPWM modulation hysteresis switch bridge arm 4 includes a first high-frequency switch tube S1 and a second high-frequency switch tube S2. The drain of the first high-frequency switch tube S1 serves as the first input end of the high-frequency SPWM modulation hysteresis switch bridge arm 4 and is connected to the first output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2, that is, the drain of the first power frequency switch tube Q1. The source of the first high-frequency switch tube S1 is connected to the drain of the second high-frequency switch tube S2, and the connection point is the midpoint of the high-frequency SPWM modulation hysteresis switch bridge arm 4, which also serves as the first output end of the high-frequency SPWM modulation hysteresis switch bridge arm 4. The source of the second high-frequency switch tube S2 serves as the second input end of the high-frequency SPWM modulation hysteresis switch bridge arm 4 and is connected to the second output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2, that is, the source of the second power frequency switch tube Q2. The equivalent junction capacitance of the first high-frequency switch tube S1 is the equivalent junction capacitance C of the first switch tube. S1 , the equivalent junction capacitance of the second high-frequency switch tube S2 is the second switch tube equivalent junction capacitance C S2 ; The body diode D of the first high-frequency switch tube S1 S1 The cathode of the DC voltage module 1 is connected to the positive output terminal, that is, the input voltage U i The anode of the body diode D S1 The anode of the second high-frequency switch tube S2 is connected to the drain of the second high-frequency switch tube S2, one end of the filter inductor L, and the high-frequency auxiliary switch and the junction capacitor energy storage and release network. S2 The cathode of the second high-frequency switch tube S2 is connected to one end of the filter inductor L and the high-frequency auxiliary switch and the junction capacitor energy storage and release network. S2 The anode of the DC voltage module 1 is connected to the negative output terminal, that is, the input voltage U i negative connection.

[0028] The filter network 3 is connected to the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm 2 and the high frequency SPWM modulation hysteresis switch bridge arm 4, and is used to filter the high frequency square wave output by the high frequency SPWM modulation hysteresis switch bridge arm 4 to obtain the output voltage U o .

[0029] The filter network 3 includes a filter inductor L and a filter capacitor C; one end of the filter inductor L is used as the input end of the filter network 3 and is connected to the first output end of the high-frequency SPWM modulation hysteresis switch bridge arm 4, the other end of the filter inductor L is connected to one end of the filter capacitor C, and the other end of the filter capacitor C is used as the output end of the filter network 3 and is connected to the first input end of the power frequency voltage commutated parallel resonant energy storage capacitor bridge arm 2; both ends of the filter capacitor C are used as the output ends of the inverter, and the output voltage is recorded as U o ;

[0030] The high-frequency auxiliary switch and the junction capacitor energy storage and release network 5 are connected to the DC voltage module 1 and the high-frequency SPWM modulation hysteresis switch bridge arm 4 to realize the soft switching of the high-frequency switch tube;

[0031] The high-frequency auxiliary switch and junction capacitor energy storage and release network 5 includes a third high-frequency switch tube S3, a fourth high-frequency switch tube S4, a resonant inductor L r , resonant energy storage capacitor C1, resonant energy storage capacitor C2; resonant inductor L r One end of the high-frequency auxiliary switch is used as the third connection end of the junction capacitor energy storage and release network, and is connected to the midpoint of the high-frequency SPWM modulation hysteresis switch bridge arm 4; the resonant inductor L r The other end is connected to the drain of the fourth high-frequency switch tube S4, the source of the fourth high-frequency switch tube S4 is connected to the source of the third high-frequency switch tube S3, and the drain of the third high-frequency switch tube S3 is connected to the midpoint of the series-connected resonant energy storage capacitor C1 and the resonant energy storage capacitor C2; one end of the series-connected resonant energy storage capacitor C1 and the resonant energy storage capacitor C2 is used as the first connection end of the high-frequency auxiliary switch and the junction capacitor energy storage and release network, and is connected to the positive output end of the DC voltage module 1, and the other end of the series-connected resonant energy storage capacitor C1 and the resonant energy storage capacitor C2 is used as the second connection end of the high-frequency auxiliary switch and the junction capacitor energy storage and release network, and is connected to the negative output end of the DC voltage module 1;

[0032] In the high-frequency auxiliary switch and junction capacitance energy storage and release network 5, C1 and C2 are used to store and release the junction capacitance energy of the main high-frequency switch tube: to realize the soft switching of the first high-frequency switch tube S1, the second high-frequency switch tube S2, the third high-frequency switch tube S3, and the fourth high-frequency switch tube S4. The high-frequency auxiliary switch and junction capacitance energy storage and release network 5 is used to realize that the junction capacitance energy between the drain and the source is released to zero by controlling the third high-frequency switch tube S3 and the fourth high-frequency switch tube S4 to lead the high-frequency SPWM modulation and lag the switch bridge arm to turn on and off.

[0033] The gates of the first high-frequency switch tube S1 , the second high-frequency switch tube S2 , the third high-frequency switch tube S3 , and the fourth high-frequency switch tube S4 are connected to the SPWM signal.

[0034] In the present invention, the first power frequency switch tube, the first high frequency switch tube, and the third high frequency switch tube constitute the inverter positive half-cycle voltage output path; the second power frequency switch tube, the second high frequency switch tube, and the fourth high frequency switch tube constitute the inverter negative half-cycle voltage output path.

[0035] The present invention realizes soft switching of all high-frequency switch tubes by transferring the energy of the junction capacitance of the high-frequency switch tubes to the energy storage capacitors C1 and C2 through the SPWM control mode in which the third high-frequency switch tube S3 and the fourth high-frequency switch tube S4 are turned on ahead of the first high-frequency switch tube S1 and the second high-frequency switch tube S2. In the positive half cycle of the output voltage, the first power frequency switch tube Q1 and the second high-frequency switch tube S2 are normally closed, the second power frequency switch tube Q2 and the third high-frequency switch tube S3 are normally turned on, and the first high-frequency switch tube S1 and the third high-frequency switch tube S3 are high-frequency switched; in the negative half cycle, the second power frequency switch tube Q2 and the first high-frequency switch tube S1 are normally closed, the first power frequency switch tube Q1 and the third high-frequency switch tube S3 are normally turned on, and the second high-frequency switch tube S2 and the fourth high-frequency switch tube S4 are high-frequency switched. The following is an ideal signal waveform. Figure 2 , Modal Figure 3-Figure 10 , Figure 11-Figure 18 , Figure 19-Figure 26 , Figure 27-Figure 34 , specifically analyze the working principle and four-stage working mode of the soft-switching inverter of the present invention, wherein the output voltage is greater than zero and the output current is greater than zero in the first stage, the output voltage is less than zero and the output current is greater than zero in the second stage, the output voltage is less than zero and the output current is less than zero in the third stage, and the output voltage is greater than zero and the output current is less than zero in the fourth stage.

[0036] The first stage of working mode 1: Figure 3 The circuit shown corresponds to Figure 2 In the interval [t0, t1] shown in the figure, the second power frequency switch tube Q2, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the second high frequency switch tube S2 are turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The current of the filter inductor L decreases linearly, and the current of the resonant inductor increases linearly. At time t1, the two are equal; the current of the body diode of the second high frequency switch tube S2 decreases to 0, the filter inductor current is positive, the output voltage is positive, and this stage ends.

[0037] Phase 1 working mode 2: Figure 4 The circuit shown corresponds to Figure 2In the interval [t1, t2] shown, the second power frequency switch tube Q2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The purpose of this time interval is to use the current of the resonant inductor to discharge the parasitic capacitance Cs1 of the first high frequency switch tube S1 to 0 and to charge the parasitic capacitance Cs2 of the second high frequency switch tube S2 to the input voltage. The filter inductor current is positive, the output voltage is positive, and this stage ends.

[0038] Phase 1 working mode 3: Figure 5 The circuit shown corresponds to Figure 2 In the interval [t2, t3] shown, the second power frequency switch tube Q2, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the first high frequency switch tube S1 body diodes are turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. After the parasitic capacitor Cs1 is discharged to 0, the first high frequency switch tube S1 is temporarily not turned on, and the current of the resonant inductor flows through the body diode of the first high frequency switch tube S1, creating a ZVS (zero voltage switching) condition for the next turn-on of the first high frequency switch tube S1. The filter inductor current is positive, the output voltage is positive, and this stage ends.

[0039] Phase 1 working mode 4: Figure 6 The circuit shown corresponds to Figure 2 In the interval [t3, t4] shown, the second power frequency switch tube Q2, the first high frequency switch tube S1, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the body diode of the first high frequency switch tube S1 are turned on, and the first power frequency switch tube Q1 and the second high frequency switch tube S2 are turned off. At this time, the current of the first high frequency switch tube S1 gradually rises from a negative value to zero and flows through the main channel and the body diode. When the current rises to zero, the body diode of the first high frequency switch tube S1 is cut off and enters the next mode. Since the drain-source voltage and current of the first high frequency switch tube S1 do not overlap at this time, soft switching is achieved, the filter inductor current is positive, the output voltage is positive, and this stage ends.

[0040] Phase 1 working mode 5: Figure 7 The circuit shown corresponds to Figure 2 In the interval [t4, t5] shown, the second power frequency switch tube Q2, the first high frequency switch tube S1, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the first power frequency switch tube Q1 and the second high frequency switch tube S2 are turned off. This modal filter inductor current flows through the first high frequency switch tube S1, and the resonant inductor current begins to linearly decrease from the maximum value to zero. The filter inductor current is positive, the output voltage is positive, and this stage ends.

[0041] Phase 1 working mode 6: Figure 8 The circuit shown corresponds to Figure 2In the interval [t5, t6] shown, the second power frequency switch tube Q2, the first high frequency switch tube S1, the body diode of the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the first power frequency switch tube Q1 and the second high frequency switch tube S2 are turned off. During the working mode 1 to the working mode 5, the energy storage capacitor C2 provides resonant energy. At the beginning of this stage, the capacitor C1 discharges to provide resonant energy, and the current of the resonant inductor charges the capacitor C2. The filter inductor current is positive, the output voltage is positive, and this stage ends.

[0042] Phase 1 working mode 7: Fig. 9 The circuit shown corresponds to Figure 2 In the interval [t6, t7] shown, the second power frequency switch tube Q2 is turned on, and the first power frequency switch tube Q1, the first high-frequency switch tube S1, the second high-frequency switch tube S2, the third high-frequency switch tube S3, and the fourth high-frequency switch tube S4 are turned off. Due to the existence of the energy storage capacitor C1, the voltage across the first high-frequency switch tube S1 will slowly drop to achieve ZVS shutdown. The filter inductor current charges the parasitic capacitor Cs1 of the first high-frequency switch tube S1 to the input DC voltage, and discharges the parasitic capacitor Cs2 of the second high-frequency switch tube S2 to 0. The filter inductor current is positive, the output voltage is positive, and this stage ends.

[0043] The first stage of working mode 8: Fig.10 The circuit shown corresponds to Figure 2 In the interval [t7, t8] shown, the second power frequency switch tube Q2 is turned on, the first power frequency switch tube Q1, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off, and the inductor current flows through the body diode of the second high frequency switch tube S2 for freewheeling. In the next mode, the third high frequency switch tube S3 starts to turn on. Since the resonant current is zero, the third high frequency switch tube S3 and the fourth high frequency switch tube S4 can achieve ZCS conduction, the filter inductor current is positive, the output voltage is positive, and this stage ends.

[0044] The second stage working mode 1: Fig.11 The circuit shown corresponds to Figure 2 In the interval [t0, t1] shown, the first power frequency switch tube Q1, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the second high frequency switch tube S2 are turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The filter inductor current decreases linearly, and the resonant inductor current increases linearly. At time t1, the two are equal, and the current of the second high frequency switch tube S2 body diode decreases to 0, the filter inductor current is positive, and the output voltage is negative, and this stage ends.

[0045] The second stage working mode 2: Fig.12 The circuit shown corresponds to Figure 2In the interval [t1, t2] shown, the first power frequency switch tube Q1, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The purpose of this time interval is to use the resonant inductor current to discharge the parasitic capacitance Cs1 of the first high frequency switch tube S1 to 0 and charge the parasitic capacitance Cs2 of the second high frequency switch tube S2 to the input voltage. The filter inductor current is positive, the output voltage is negative, and this stage ends.

[0046] The second stage working mode 3: Fig.13 The circuit shown corresponds to Figure 2 In the interval [t2, t3] shown, the first power frequency switch tube Q1, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the first high frequency switch tube S1 body diode are turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. After the parasitic capacitor Cs1 is discharged to 0, the first high frequency switch tube S1 is temporarily not turned on, and the resonant inductor current flows through the first high frequency switch tube S1 body diode to create ZVS conditions for the next turn-on of the first high frequency switch tube S1. The filter inductor current is positive, the output voltage is negative, and this stage ends.

[0047] The second stage working mode 4: Fig.14 The circuit shown corresponds to Figure 2 In the interval [t3, t4] shown, the first power frequency switch tube Q1, the first high frequency switch tube S1, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the body diode of the first high frequency switch tube S1 are turned on, and the second power frequency switch tube Q2 and the second high frequency switch tube S2 are turned off. At this time, the current of the first high frequency switch tube S1 begins to gradually rise from a negative value to zero and flows through the main channel and the body diode. When the current rises to zero, the body diode of the first high frequency switch tube S1 is cut off and enters the next mode. Since the drain-source voltage and current of the first high frequency switch tube S1 do not overlap at this time, soft switching is achieved, the filter inductor current is positive, the output voltage is negative, and this stage ends.

[0048] Second stage working mode 5: Fig.15 The circuit shown corresponds to Figure 2 In the interval [t4, t5] shown, the first power frequency switch tube Q1, the first high frequency switch tube S1, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the second power frequency switch tube Q2 and the second high frequency switch tube S2 are turned off. In this mode, the filter inductor current flows through the first high frequency switch tube S1, and the resonant inductor current begins to linearly decrease from the maximum value to zero. The filter inductor current is positive, the output voltage is negative, and this stage ends.

[0049] The second stage working mode 6: Fig.16 The circuit shown corresponds to Figure 2In the interval [t5, t6] shown, the first power frequency switch tube Q1, the first high frequency switch tube S1, the body diode of the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the second power frequency switch tube Q2 and the second high frequency switch tube S2 are turned off. During the working mode 1 to the working mode 5, the energy storage capacitor C2 provides resonant energy. At the beginning of this stage, the capacitor C1 discharges to provide resonant energy, and the resonant inductor current charges the capacitor C2. The current direction on the output filter inductor L is downward, the filter inductor current is positive, and the output voltage is negative. This stage ends.

[0050] Second stage working mode 7: Fig.17 The circuit shown corresponds to Figure 2 In the interval [t6, t7] shown, the first power frequency switch tube Q1 is turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off. Due to the existence of the energy storage capacitor C1, the voltage across the first high frequency switch tube S1 will slowly drop to achieve ZVS shutdown, and the filter inductor current charges the parasitic capacitor Cs1 of the first high frequency switch tube S1 to the input DC voltage, and discharges the parasitic capacitor Cs2 of the second high frequency switch tube S2 to 0. The filter inductor current is positive, the output voltage is negative, and this stage ends.

[0051] The second stage working mode 8: Fig.18 The circuit shown corresponds to Figure 2 In the interval [t7, t8] shown, the first power frequency switch tube Q1 is turned on, the second power frequency switch tube Q2, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off, and the filter inductor current flows through the body diode of the second high frequency switch tube S2 for freewheeling, and the third high frequency switch tube S3 in the next mode starts to turn on. Since the resonant inductor current is already zero, the third high frequency switch tube S2 and the fourth high frequency switch tube S4 can achieve ZCS conduction, the filter inductor current is positive, the output voltage is negative, and this stage ends.

[0052] The third stage working mode 1: Fig.19 The circuit shown corresponds to Figure 2 In the interval [t0, t1] shown in the figure, the first power frequency switch tube Q1, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the first high frequency switch tube S1 body diode are turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The filter inductor current decreases linearly, and the resonant inductor current increases linearly. At time t1, the two are equal. The current of the first high frequency switch tube S1 body diode decreases to 0, the filter inductor current and the output voltage are negative, and this stage ends.

[0053] The third stage working mode 2: Fig. 20 The circuit shown corresponds to Figure 2In the interval [t1, t2] shown, the first power frequency switch tube Q1, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The purpose of this time interval is to use the resonant inductor current to charge the parasitic capacitance Cs1 of the first high frequency switch tube S1 to the input voltage and discharge the parasitic capacitance Cs2 of the second high frequency switch tube S2 to zero, the filter inductor current and the output voltage are negative, and this stage ends.

[0054] The third stage working mode 3: Fig.21 The circuit shown corresponds to Figure 2 In the interval [t2, t3] shown, the first power frequency switch tube Q1, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the second high frequency switch tube S2 are turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. After the parasitic capacitor Cs2 is discharged to 0, the second high frequency switch tube S2 is temporarily not turned on, and the resonant inductor current flows through the body diode of the second high frequency switch tube S2 to create a ZVS condition for the next conduction of the second high frequency switch tube S2. The filter inductor current and the output voltage are negative, and this stage ends.

[0055] The third stage working mode 4: Fig. 22 The circuit shown corresponds to Figure 2 In the interval [t3, t4] shown, the body diodes of the first power frequency switch tube Q1, the second high frequency switch tube S2, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the second high frequency switch tube S2 are turned on, and the second power frequency switch tube Q2 and the first high frequency switch tube S1 are turned off. At this time, the current of the second high frequency switch tube S2 begins to gradually rise from a negative value to zero and flows through the main channel and the body diode. When the current rises to zero, the body diode of the second high frequency switch tube S2 is cut off and enters the next mode. Since the drain-source voltage and current of the second high frequency switch tube S2 do not overlap at this time, soft switching is achieved, and the filter inductor current and output voltage are negative, and this stage ends.

[0056] The third stage working mode 5: Fig.23 The circuit shown corresponds to Figure 2 In the interval [t4, t5] shown, the first power frequency switch tube Q1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the second power frequency switch tube Q2 and the first high frequency switch tube S1 are turned off. In this mode, the filter inductor current flows through the second high frequency switch tube S2, and the resonant inductor current begins to linearly decrease from the maximum value to zero. The filter inductor current and the output voltage are negative, and this stage ends.

[0057] The third stage working mode 6: Fig.24 The circuit shown corresponds to Figure 2In the interval [t5, t6] shown, the body diodes of the first power frequency switch tube Q1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the second power frequency switch tube Q2 and the first high frequency switch tube S1 are turned off. During the working mode 1 to the working mode 5, the energy storage capacitor C1 provides resonant energy. At the beginning of this stage, the capacitor C2 discharges to provide resonant energy, and the resonant inductor current charges the capacitor C1. The filter inductor current and the output voltage are negative, and this stage ends.

[0058] The third stage working mode 7: Fig.25 The circuit shown corresponds to Figure 2 In the interval [t6, t7] shown, the first power frequency switch tube Q1 is turned on, and the second power frequency switch tube Q2, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off. Due to the existence of the energy storage capacitor C2, the voltage across the first high frequency switch tube S2 will slowly drop to achieve ZVS shutdown, and the filter inductor current charges the parasitic capacitor Cs2 of the second high frequency switch tube S2 to the input DC voltage, and discharges the parasitic capacitor Cs1 of the first high frequency switch tube S1 to zero, the filter inductor current and the output voltage are negative, and this stage ends.

[0059] The third stage working mode 8: Fig.26 The circuit shown corresponds to Figure 2 In the interval [t7, t8] shown, the first power frequency switch tube Q1 is turned on, the second power frequency switch tube Q2, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off, and the filter inductor current flows through the body diode of the first high frequency switch tube S1 for freewheeling, and the third high frequency switch tube S3 in the next mode starts to turn on. Since the resonant inductor current is already zero, the third high frequency switch tube S3 and the fourth high frequency switch tube S4 can achieve ZCS conduction, the filter inductor current and the output voltage are negative, and this stage ends.

[0060] The fourth stage of working mode 1: Fig. 27 The circuit shown corresponds to Figure 2 In the interval [t0, t1] shown, the second power frequency switch tube Q2, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the first high frequency switch tube S1 are turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The filter inductor current decreases linearly, and the resonant inductor current increases linearly. At time t1, the two are equal. The current of the body diode of the first high frequency switch tube S1 decreases to 0, the filter inductor current is negative, and the output voltage is positive, and this stage ends.

[0061] The fourth stage of working mode 2: Fig.28 The circuit shown corresponds to Figure 2In the interval [t1, t2] shown, the second power frequency switch tube Q2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. The purpose of this time interval is to use the resonant inductor current to charge the parasitic capacitance Cs1 of the first high frequency switch tube S1 to the input voltage and discharge the parasitic capacitance Cs2 of the second high frequency switch tube S2 to zero. The filter inductor current is negative, the output voltage is positive, and this stage ends.

[0062] The fourth stage of working mode 3: Fig.29 The circuit shown corresponds to Figure 2 In the interval [t2, t3] shown, the second power frequency switch tube Q2, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the second high frequency switch tube S2 are turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, and the second high frequency switch tube S2 are turned off. After the parasitic capacitor Cs2 is discharged to 0, the second high frequency switch tube S2 is temporarily not turned on, and the resonant inductor current flows through the second high frequency switch tube S2 body diode, creating a ZVS condition for the next second high frequency switch tube S2 to turn on. The filter inductor current is negative, the output voltage is positive, and this stage ends.

[0063] The fourth stage of working mode 4: Fig.30 The circuit shown corresponds to Figure 2 In the interval [t3, t4] shown, the second power frequency switch tube Q2, the second high frequency switch tube S2, the third high frequency switch tube S3, the fourth high frequency switch tube S4, and the body diode of the second high frequency switch tube S2 are turned on, and the first power frequency switch tube Q1 and the first high frequency switch tube S1 are turned off. At this time, the current of the second high frequency switch tube S2 begins to gradually rise from a negative value to zero and flows through the main channel and the body diode. When the current rises to zero, the body diode of the second high frequency switch tube S2 is cut off and enters the next mode. Since the drain-source voltage and current of the second high frequency switch tube S2 do not overlap at this time, soft switching is achieved, the filter inductor current is negative, the output voltage is positive, and this stage ends.

[0064] The fourth stage of working mode 5: Fig.31 The circuit shown corresponds to Figure 2 In the interval [t4, t5] shown, the second power frequency switch tube Q2, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the first power frequency switch tube Q1 and the first high frequency switch tube S1 are turned off. In this mode, the filter inductor current flows through the second high frequency switch tube S2, and the resonant inductor current begins to linearly decrease from the maximum value to zero. The filter inductor current is negative, the output voltage is positive, and this stage ends.

[0065] The fourth stage of working mode 6: Fig.32 The circuit shown corresponds to Figure 2In the interval [t5, t6] shown, the body diodes of the second power frequency switch tube Q2, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned on, and the first power frequency switch tube Q1 and the first high frequency switch tube S1 are turned off. During the working mode 1 to the working mode 5, the energy storage capacitor C1 provides resonant energy. At the beginning of this stage, the capacitor C2 discharges to provide resonant energy, and the resonant inductor current charges the capacitor C1. The filter inductor current is negative, and the output voltage is positive. This stage ends.

[0066] The fourth stage of working mode 7: Fig.33 The circuit shown corresponds to Figure 2 In the interval [t6, t7] shown, the second power frequency switch tube Q2 is turned on, and the first power frequency switch tube Q1, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off. Due to the existence of the energy storage capacitor C2, the voltage across the first high frequency switch tube S2 will slowly drop to achieve ZVS shutdown, and the filter inductor current charges the parasitic capacitor Cs2 of the second high frequency switch tube S2 to the input DC voltage, and discharges the parasitic capacitor Cs1 of the first high frequency switch tube S1 to zero, the filter inductor current is negative, the output voltage is positive, and this stage ends.

[0067] The fourth stage of working mode 8: Fig.34 The circuit shown corresponds to Figure 2 In the interval [t7, t8] shown, the second power frequency switch tube Q2 is turned on, the first power frequency switch tube Q2, the first high frequency switch tube S1, the second high frequency switch tube S2, the third high frequency switch tube S3, and the fourth high frequency switch tube S4 are turned off, and the filter inductor current flows through the body diode of the first high frequency switch tube S1 for freewheeling, and the third high frequency switch tube S3 in the next mode starts to turn on. Since the resonant inductor current is already zero, the third high frequency switch tube S3 and the fourth high frequency switch tube S4 can achieve ZCS conduction, the filter inductor current is negative, the output voltage is positive, and this stage ends.

[0068] Analysis of the inverter working mode of the present invention shows that the circuit has the following advantages:

[0069] (1) The inverter uses relatively few active and passive components.

[0070] (2) There is no need to set a dead zone for the inverter's high-frequency switching tube.

[0071] (3) All high-frequency switching tubes can achieve full-range soft switching.

[0072] (4) The auxiliary high-frequency control method is to conduct the main switch tube ahead of time, and the control method is simple.

[0073] The "first" and "second" in the names such as "first" and "second" (if any) mentioned in the embodiments of the present application are only used as name identifiers and do not represent the first or second in order.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A non-shoot-through active auxiliary full-range soft switching inverter, characterized in that: include: A DC voltage module, including a positive output terminal and a negative output terminal, for providing an input voltage for the inverter; The power frequency voltage commutation parallel resonant energy storage capacitor bridge arm is connected to the DC voltage module and includes a power frequency switch bridge arm composed of two power frequency switch tubes; it is used to output a power frequency AC square wave in the case of a single power supply input; The high-frequency SPWM modulation hysteresis switch bridge arm is connected to the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm, and includes a high-frequency switch bridge arm composed of two high-frequency switch tubes, and is used to perform SPWM modulation on the power frequency AC square wave voltage output by the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm, so as to output a high-frequency square wave after unipolar modulation; A filter network is connected to the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm and the high frequency SPWM modulation hysteresis switch bridge arm, and is used for filtering the high frequency square wave output by the high frequency SPWM modulation hysteresis switch bridge arm to obtain an output voltage; The high-frequency auxiliary switch and the junction capacitor energy storage and release network are connected to the DC voltage module and the high-frequency SPWM modulation hysteresis switch bridge arm to realize the soft switching of the high-frequency switch tube;.

2. The non-shoot-through active auxiliary full-range soft switching inverter according to claim 1, characterized in that: The power frequency voltage commutated parallel resonant energy storage capacitor bridge arm includes a first power frequency switch tube Q1 and a second power frequency switch tube Q2. The drain of the first power frequency switch tube Q1 is connected to the positive output end of the DC voltage module, that is, the input voltage U i The positive electrode of the first power frequency switch tube Q1 is connected, the drain of the first power frequency switch tube Q1 serves as the first output end of the power frequency voltage commutated parallel resonant energy storage capacitor bridge arm, the source of the first power frequency switch tube Q1 is connected to the drain of the second power frequency switch tube Q2 and is grounded, and the connection point serves as the first input end of the power frequency voltage commutated parallel resonant energy storage capacitor bridge arm; the gate of the first power frequency switch tube Q1 is connected to the gate of the second power frequency switch tube Q2; the source of the second power frequency switch tube Q2 is connected to the negative output end of the DC voltage module; the source of the second power frequency switch tube Q2 serves as the second output end of the power frequency voltage commutated parallel resonant energy storage capacitor bridge arm, and the first output end and the second output end of the power frequency voltage commutated parallel resonant energy storage capacitor bridge arm output a power frequency AC square wave.

3. The non-shoot-through active auxiliary full-range soft switching inverter according to claim 1, characterized in that: The high-frequency SPWM modulation hysteresis switch bridge arm includes a first high-frequency switch tube S1 and a second high-frequency switch tube S2. The drain of the first high-frequency switch tube S1 serves as the first input end of the high-frequency SPWM modulation hysteresis switch bridge arm and is connected to the first output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm; the source of the first high-frequency switch tube S1 is connected to the drain of the second high-frequency switch tube S2, and the connection point serves as the first output end of the high-frequency SPWM modulation hysteresis switch bridge arm; the source of the second high-frequency switch tube S2 serves as the second input end of the high-frequency SPWM modulation hysteresis switch bridge arm and is connected to the second output end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm.

4. The non-shoot-through active auxiliary full-range soft switching inverter according to claim 1, characterized in that: The filter network includes a filter inductor L and a filter capacitor C; one end of the filter inductor L is used as the input end of the filter network and is connected to the first output end of the high-frequency SPWM modulation hysteresis switch bridge arm, the other end of the filter inductor L is connected to one end of the filter capacitor C, and the other end of the filter capacitor C is used as the output end of the filter network and is connected to the first input end of the power frequency voltage commutation parallel resonant energy storage capacitor bridge arm; both ends of the filter capacitor C are used as the output ends of the inverter, and the output voltage U o .

5. The non-shoot-through active auxiliary full-range soft switching inverter according to claim 1, characterized in that: The high-frequency auxiliary switch and junction capacitor energy storage and release network includes a third high-frequency switch tube S3, a fourth high-frequency switch tube S4, a resonant inductor L r , resonant energy storage capacitor C1, resonant energy storage capacitor C2; resonant inductor L r One end of the resonant inductor L is used as the third connection end of the high-frequency auxiliary switch and the junction capacitor energy storage and release network, and is connected to the first output end of the high-frequency SPWM modulation hysteresis switch bridge arm; r The other end is connected to the drain of the fourth high-frequency switch tube S4, the source of the fourth high-frequency switch tube S4 is connected to the source of the third high-frequency switch tube S3, and the drain of the third high-frequency switch tube S3 is connected to the midpoint of the series-connected resonant energy storage capacitor C1 and the resonant energy storage capacitor C2; one end of the series-connected resonant energy storage capacitor C1 and the resonant energy storage capacitor C2 serves as the first connection end of the high-frequency auxiliary switch and the junction capacitor energy storage and release network, and is connected to the positive output end of the DC voltage module, and the other end of the series-connected resonant energy storage capacitor C1 and the resonant energy storage capacitor C2 serves as the second connection end of the high-frequency auxiliary switch and the junction capacitor energy storage and release network, and is connected to the negative output end of the DC voltage module.

6. The non-shoot-through active auxiliary full-range soft switching inverter according to claim 1, characterized in that: The first power-frequency switch tube in the power-frequency voltage-commutated parallel resonant energy storage capacitor bridge arm, the first high-frequency switch tube in the high-frequency SPWM modulation lagging switch bridge arm, the high-frequency auxiliary switch and the third high-frequency switch tube in the junction capacitor energy storage and release network together constitute the inverter positive half-cycle voltage output path; the second power-frequency switch tube in the power-frequency voltage-commutated parallel resonant energy storage capacitor bridge arm, the second high-frequency switch tube in the high-frequency SPWM modulation lagging switch bridge arm, the high-frequency auxiliary switch and the fourth high-frequency switch tube in the junction capacitor energy storage and release network together constitute the inverter negative half-cycle voltage output path.

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