Push-pull inverter circuit and high-frequency power supply device

Abstract

The invention discloses a push-pull inverter circuit and a high-frequency power supply device. The circuit comprises an input interface and a voltage transformation module, a first switch module is connected between a first end and a grounding end of a primary side coil, and a control end of the first switch module is used for inputting a first control signal; the second switch module is connected between the second end of the primary side coil and the grounding end, and the control end of the second switch module is used for inputting a second control signal; the resonance network is connected with the primary side coil, the first switch module and the second switch module, and the resonance network is used for adjusting soft switching of the first switch module according to the first control signal; and the second switch module is adjusted to perform soft switching according to the second control signal. According to the push-pull inverter circuit, transient voltage and current peaks in the switching process of the switch module can be reduced, the loss of the push-pull inverter circuit under high frequency is reduced, the switch module can work at low temperature conveniently, the reliability of the circuit is improved, the service life of the circuit is prolonged, the working frequency of the push-pull inverter circuit is improved, and the size of the push-pull inverter circuit is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of circuit technology, and in particular to a push-pull inverter circuit and a high-frequency power supply device. Background Art

[0002] High-frequency inverter circuits are widely used in information technology, industrial automation, medical equipment, aerospace and other fields. The push-pull inverter circuit of the prior art uses a switch tube made of silicon devices. However, due to the large gate charge of silicon devices, its switching frequency is limited and generally cannot exceed 1MHz. In addition, the junction capacitance between the drain and source of silicon devices is large, resulting in a high voltage spike when the switch tube switches state.

[0003] Therefore, the push-pull inverter circuit in the prior art has the problems of low frequency and voltage spikes during state switching, which leads to defects such as low efficiency and poor reliability of the push-pull inverter circuit. Summary of the invention

[0004] The embodiment of the present invention provides a push-pull inverter circuit and a high-frequency power supply device to solve the problem of low operating frequency of the push-pull inverter circuit in the prior art.

[0005] In order to achieve the above technical problems, the present invention adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a push-pull inverter circuit, comprising:

[0007] Input interface, used for inputting direct current signal;

[0008] A transformer module, wherein the center tap of the primary coil of the transformer module is connected to the input interface, and the secondary coil of the transformer module is used to connect to a load;

[0009] The first switch module is connected between the first end of the primary coil and the ground end, and the control end of the first switch module is used to input a first control signal;

[0010] The second switch module is connected between the second end of the primary coil and the ground end, and the control end of the second switch module is used to input a second control signal;

[0011] A resonant network, wherein the resonant network is connected to the primary coil and the first switch module and the second switch module, and the resonant network is used to adjust the first switch module to perform soft switching according to the first control signal; and to adjust the second switch module to perform soft switching according to the second control signal.

[0012] Optionally, the first end of the resonant network is connected to the input interface, the second end of the resonant network is connected to the center tap, the third end of the resonant network is connected to the first end of the first switch module, and the fourth end of the resonant network is connected to the second end of the first switch module; the fifth end of the resonant network is connected to the first end of the second switch module, and the sixth end of the resonant network is connected to the second end of the second switch module;

[0013] The resonant network is used to adjust the first switch module to be turned on according to the first control signal when the voltage between the second end and the first end is zero; and to adjust the second switch module to be turned on according to the second control signal when the voltage between the second end and the first end is zero.

[0014] Optionally, the first switch module includes a first gallium nitride switch tube;

[0015] The second switch module includes a second gallium nitride switch tube;

[0016] The resonant network is used to adjust the first gallium nitride switch tube to be turned on according to the first control signal when the voltage between the drain and the source is zero; and to adjust the second gallium nitride switch tube to be turned on according to the second control signal when the voltage between the drain and the source is zero.

[0017] Optionally, the resonant network comprises:

[0018] A first frequency modulation unit, wherein the first frequency modulation unit is connected between the input interface and the center tap of the primary coil;

[0019] A first energy storage unit, wherein the first energy storage unit is connected between the first end and the second end of the first switch module;

[0020] A second energy storage unit, wherein the second energy storage unit is connected between the first end and the second end of the second switch module.

[0021] Optionally, the first frequency modulation unit includes a first inductor, and the first inductor is connected between the input interface and the center tap of the primary coil;

[0022] The first energy storage unit includes a first capacitor, and the first capacitor is connected between the first end and the second end of the first switch module;

[0023] The second energy storage unit includes a second capacitor connected between the first end and the second end of the second switch module.

[0024] Optionally, the resonant network further includes:

[0025] A second frequency modulation unit, wherein the second frequency modulation unit is connected between the secondary coil and the load, and the second frequency modulation unit is used to form resonance with the first frequency modulation unit, the first energy storage unit and the second energy storage unit.

[0026] Optionally, the second frequency modulation unit includes:

[0027] A second inductor is connected between the secondary coil and the load, and is used to form resonance with the first inductor, the first capacitor and the second capacitor.

[0028] Optionally, the push-pull inverter circuit further includes:

[0029] A third energy storage module, wherein the third energy storage module is connected between the input interface and the ground terminal, and is used for temporarily storing the DC signal input from the input interface when the first switch module and the second switch module perform a switching action.

[0030] Optionally, the third energy storage module includes:

[0031] A third capacitor is connected between the input interface and the ground terminal, and is used to temporarily store the DC signal input from the input interface each time the first switch module and the second switch module perform a switching action.

[0032] According to another aspect of the present invention, this embodiment provides a high-frequency power supply device, including: the push-pull inverter circuit proposed in any item of the first aspect.

[0033] The technical solution of the embodiment of the present invention realizes the inversion of the push-pull inverter circuit by controlling the switching frequency of the first switch module and the second switch module, and realizes the soft switching of the switch module through the resonant network. Due to the use of soft switching technology, this solution can reduce the transient voltage and current spikes during the switching process of the switch module; secondly, soft switching reduces the switching loss of the device, so this solution can significantly improve the overall energy conversion efficiency of the push-pull inverter circuit, realize the push-pull inverter circuit to work at an ultra-high frequency above 4MHz, and can effectively increase the operating frequency of the push-pull inverter circuit. In addition, the technical solution of the embodiment of the present invention facilitates the switch module to work at a lower temperature, improves the reliability and service life of the circuit, and can reduce the volume of the push-pull inverter circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0035] Figure 1 is a schematic diagram of a push-pull inverter circuit provided by an embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of another push-pull inverter circuit provided by an embodiment of the present invention;

[0037] Figure 3 is a temperature test result diagram of a push-pull inverter circuit of the prior art provided by an embodiment of the present invention;

[0038] Figure 4 is a temperature test result diagram of a push-pull inverter circuit provided by an embodiment of the present invention;

[0039] Figure 5 This is another schematic diagram of a push-pull inverter circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0041] Based on the above technical problems, this embodiment proposes the following solutions:

[0042] Figure 1 FIG. 1 is a schematic diagram of a push-pull inverter circuit provided by an embodiment of the present invention. Figure 1 As shown, the push-pull inverter circuit includes: an input interface V DC , used to input a DC signal; a transformer module 110, a center tap 112 of a primary coil 111 of the transformer module 110 and an input interface V DCThe secondary coil 113 of the transformer module is used to connect the load 150; the first switch module 120 is connected between the first end of the primary coil 111 and the ground end, and the control end G1 of the first switch module 120 is used to input the first control signal; the second switch module 130 is connected between the second end of the primary coil 111 and the ground end, and the control end G2 of the second switch module 130 is used to input the second control signal; the resonant network 140, the resonant network 140 is connected to the primary coil 111 and the first switch module 120 and the second switch module 130, and the resonant network 140 is used to adjust the first switch module 120 to soft switch according to the first control signal; and adjust the second switch module 130 to soft switch according to the second control signal.

[0043] Among them, the input interface V DC Refers to the DC voltage input of the push-pull inverter circuit, which is provided by a battery, a DC power supply or other DC power supply device. For example, the input interface V DC The voltage provided can be 12V, 24V or 48V etc.

[0044] The transformer module 110 refers to a device used to adjust and convert voltage in a push-pull inverter circuit, which can be a step-up device or a step-down device. Exemplarily, the transformer module 110 can be a transformer with a center tap. The primary coil 111 refers to a coil located at the input end of the transformer, which is responsible for receiving the input voltage and generating a magnetic field. The center tap 112 refers to a connection point located in the middle part of the primary coil 111 or the secondary coil 113. Through the center tap 112, you can choose to use the voltage of the entire coil, or only use the voltage of the part of the coil from the center tap 112 to either end of the coil. The secondary coil 113 refers to the coil in the transformer opposite to the primary coil 111, which is responsible for inducing voltage from the magnetic field and outputting it to the load 150. The secondary coil 113 converts the magnetic energy generated by the primary coil 111 into electrical energy and outputs it to the connected load 150.

[0045] The load 150 refers to a device or component connected to the output end of the circuit, which consumes electrical energy to perform a specific function. For example, the load 150 may be a motor, a light, a heater, an electronic device, and the like.

[0046] The first switch module 120 refers to a switch device in the DC circuit part of the push-pull inverter circuit that is responsible for controlling the flow of current. The main function of the first switch module 120 is to adjust the output voltage and frequency of the circuit through fast switching operations, thereby achieving efficient power conversion and output control. Exemplarily, the first switch module 120 can be a MOSFET or an IGBT.

[0047] The first end of the primary coil 111 refers to a connection point of the primary coil 111, which is connected to the first switch module 120 as an access point for the input power supply. The ground terminal refers to the connection point where the primary coil 111 is connected to the ground wire 160, which is used to ensure the safety and stability of the transformer and prevent voltage drift or interference. The control terminal G1 refers to an interface on the first switch module 120 for receiving a control signal to adjust the on and off states of the switch. Through the control signal received by the control terminal G1, the first switch module 120 can quickly switch between on and off to adjust the current flow direction. The first control signal refers to a signal generated by an external control module and input to the control terminal G1 of the first switch module 120, which is used to control the state of the switch. Exemplarily, when the first control signal is at a high level, the first switch module 120 is turned on; when the signal is at a low level, the first switch module 120 is turned off, thereby achieving control of the current.

[0048] The second switch module 130 refers to another switch device in the DC circuit part of the push-pull inverter circuit that is responsible for controlling the flow of current. The main function of the second switch module 130 is to adjust the output voltage and frequency of the circuit through fast switching operations, thereby achieving efficient power conversion and output control. Exemplarily, the second switch module 130 can be a MOSFET or an IGBT, etc.

[0049] The second end of the primary coil 111 refers to another connection point of the primary coil 111, which is connected to the second switch module 130 as an access point for the input power supply. The control terminal G2 refers to an interface on the second switch module 130 for receiving a control signal to adjust the on and off states of the switch. Through the control signal received by the control terminal G2, the second switch module 130 can quickly switch between on and off to adjust the current flow direction. The second control signal refers to a signal generated by an external control module and input to the control terminal G2 of the second switch module 130, which is used to control the state of the switch. Exemplarily, when the second control signal is at a high level, the second switch module 130 is turned on; when the signal is at a low level, the second switch module 130 is turned off, thereby achieving control of the current.

[0050] The resonant network 140 provided in this embodiment is a circuit in a push-pull inverter circuit for improving energy conversion efficiency, reducing distortion of current waveform, and ensuring stability of output voltage. Soft switching refers to a switching technology that reduces switching losses and electromagnetic interference by reducing voltage and current spikes generated during the switching process. Soft switching controls the switching process of the switching device by using a resonant circuit (such as an LC resonant circuit) so that the voltage and current are close to zero during switching to achieve a smooth transition, which helps to reduce transient voltage and current fluctuations in the switch.

[0051] In the embodiment of the present invention, when the first switch module 120 is turned on, the input interface V DC The input DC current flows through the center tap 112 of the transformer module 110, and flows into the ground wire 160 through the first switch module 120. That is, the direction of the current flowing through the primary coil 111 of the transformer module 110 is to flow out of the same-name end of the transformer coil, so the current flowing out of the same-name end of the transformer coil is induced in the secondary coil 113 of the transformer module 110. When the second switch module 130 is turned on, the input interface V DC The input DC current flows through the center tap 112 of the transformer module 110, and flows into the ground wire 160 through the second switch module 130. That is, the direction of the current flowing through the primary coil 111 of the transformer module 110 is to flow into the same-name end of the transformer coil, so the current flowing into the same-name end of the transformer coil is induced in the secondary coil 113 of the transformer module 110. By controlling the first switch module 120 and the second switch module 130 to be alternately turned on at a certain frequency, a current whose direction changes at a corresponding frequency is generated in the secondary coil 113 of the transformer module, thereby realizing the inversion from DC to AC. Among them, when the resonant network 140 operates at its resonant frequency, the energy exchange between the inductor and the capacitor reaches the optimal state. At this time, the first control signal and the second control signal are used to control the first switch module 120 and the second switch module 130 to switch, which can realize the soft switching of the circuit.

[0052] The technical solution of the embodiment of the present invention realizes the inversion of the push-pull inverter circuit by controlling the switching frequency of the first switch module 120 and the second switch module 130, and realizes the soft switching of the switch module through the resonant network 140. Due to the use of soft switching technology, this solution can reduce the transient voltage and current spikes during the switching process of the switch module; secondly, soft switching reduces the switching loss of the device, so this solution can significantly improve the overall energy conversion efficiency of the push-pull inverter circuit, realize the push-pull inverter circuit working at an ultra-high frequency of more than 4MHz, and can effectively improve the operating frequency of the push-pull inverter circuit.

[0053] Figure 2 is a schematic diagram of another push-pull inverter circuit provided by an embodiment of the present invention. Optionally, based on the above embodiment, Figure 2 As shown, the first end of the resonant network 140 is connected to the input interface V DCThe second end of the resonant network 140 is connected to the center tap 112, the third end of the resonant network 140 is connected to the first end of the first switch module 120, and the fourth end of the resonant network is connected to the second end of the first switch module 120; the fifth end of the resonant network 140 is connected to the first end of the second switch module 130, and the sixth end of the resonant network 140 is connected to the second end of the second switch module 130; the resonant network 140 is used to adjust the first switch module 120 to open according to the first control signal when the voltage between the second end and the first end is zero; and adjust the second switch module 130 to open according to the second control signal when the voltage between the second end and the first end is zero.

[0054] Specifically, the first end of the resonant network 140 is a connection point in the resonant network 140 and is connected to the input interface V DC The first switching module 120 is connected to the resonant network 140 to receive a direct current. The second end of the resonant network 140 is another connection point in the resonant network 140, which is connected to the center tap 112. The third end of the resonant network 140 is another connection point in the resonant network 140, which is connected to the first end of the first switch module 120. The fourth end of the resonant network 140 is another connection point in the resonant network 140, which is connected to the second end of the first switch module 120. The fifth end of the resonant network 140 is another connection point in the resonant network 140, which is connected to the first end of the second switch module 130. The third end of the resonant network 140 is another connection point in the resonant network 140, which is connected to the second end of the second switch module 130.

[0055] In the embodiment of the present invention, since the resonant network 140 has the structure of an LC resonant circuit, it can rely on the phase relationship between the current and the voltage in the push-pull inverter circuit to control the first switch module 120 and the second switch module 130 to perform switching when the voltage is almost zero, that is, to achieve soft switching.

[0056] Optionally, based on the above embodiments, continue to refer to Figure 2 The first switch module 120 may include a first gallium nitride switch tube 121; the second switch module 130 may include a second gallium nitride switch tube 131; the resonant network 140 is used to adjust the first gallium nitride switch tube 121 to be turned on according to the first control signal when the voltage between the drain and the source is zero; and to adjust the second gallium nitride switch tube 131 to be turned on according to the second control signal when the voltage between the drain and the source is zero.

[0057] Specifically, a gallium nitride switch tube refers to a semiconductor switching device made of gallium nitride material, which is mainly used for efficient power conversion and signal processing. Compared with traditional silicon switch tubes, gallium nitride switch tubes have higher electron mobility, lower on-resistance and higher voltage resistance, so they are used in higher frequency and high power scenarios. The push-pull inverter circuit provided in this embodiment adopts a gallium nitride switch tube and utilizes the excellent characteristics of gallium nitride materials. The switch device can perform fast switching operations, so that the circuit can be used in ultra-high frequency scenarios exceeding 4MHz.

[0058] The first GaN switch tube 121 refers to the switch device in the first switch module 120. The second GaN switch tube 131 refers to the switch device in the second switch module 130. The source refers to a pin of the GaN switch tube, which is usually used to introduce current and provide a stable voltage reference for the device. The drain refers to another pin of the GaN switch tube, which is responsible for collecting the current flowing from the source and transmitting it to the load or other components of the circuit.

[0059] In the embodiment of the present invention, the gallium nitride switch tube has a lower gate charge and drain-source junction capacitance, which can reduce the driving loss and switching loss of the switch tube at high frequency. In combination with the resonant network 140, soft switching is realized, and the first gallium nitride switch tube 121 and the second gallium nitride switch tube 131 are controlled to be turned on at a voltage level of zero, so that the push-pull inverter circuit can operate at ultra-high frequency (above 4MHz). In addition, compared with the push-pull inverter circuit provided by the prior art, the push-pull inverter circuit provided by the embodiment of the present invention adopts soft switching technology, so that there is basically no voltage spike at both ends of the gallium nitride device, so there is no need for an RC absorption network, and compared with the push-pull inverter circuit of the prior art, its board area can be reduced by at least 30%.

[0060] Specifically, Figure 3 This is a temperature test result diagram of a push-pull inverter circuit in the prior art provided by an embodiment of the present invention. Figure 4 1 is a temperature test result diagram of a push-pull inverter circuit provided by an embodiment of the present invention. Figure 3 and Figure 4 As shown, the input interface V of the push-pull inverter circuit provided by the prior art and the embodiment of the present invention DC The DC voltage of 12V is connected, and the switching frequency is 4MHz. The temperature of the push-pull inverter circuit provided by the embodiment of the present invention is more than 50 degrees Celsius lower than that of the traditional silicon device solution. This is because the use of gallium nitride devices and resonant soft switches greatly reduces the loss of the push-pull inverter circuit at high frequencies, allowing the switching devices to work at lower temperatures, thereby improving the reliability and service life of the circuit.

[0061] The technical solution of the embodiment of the present invention uses the resonant network 140 to turn off the switch device of the push-pull inverter circuit when the voltage is zero; by using the gallium nitride switch tube, the push-pull inverter circuit can be used in scenarios exceeding 4MHz. This solution can reduce the transient voltage and current spikes of the switch module during the switching process, and improve the overall energy conversion efficiency of the push-pull inverter circuit; at the same time, it reduces the board area and transformer volume of the push-pull inverter circuit, and increases the operating frequency of the push-pull inverter circuit, so that the circuit can work in scenarios above 4MHz.

[0062] Optionally, based on the above embodiments, continue to refer to Figure 2 The resonant network 140 may include: a first frequency modulation unit connected to the input interface V DC and the center tap 112 of the primary coil 111; a first energy storage unit, the first energy storage unit is connected between the first end and the second end of the first switch module 120; a second energy storage unit, the second energy storage unit is connected between the first end and the second end of the second switch module 130.

[0063] The first frequency modulation unit refers to a unit used to adjust the resonant frequency in the resonant network 140. When current flows through the first frequency modulation unit, a magnetic field is generated and energy is stored. This energy can be released when the current changes, thereby affecting the working state of the circuit.

[0064] Specifically, the first energy storage unit refers to a unit for storing energy in the resonant network 140. When current flows into the first energy storage unit, charges are accumulated and an electric field is formed, thereby storing energy. When the current changes, the stored electric energy is released, affecting the behavior of the resonant network 140. The second energy storage unit refers to another unit for storing energy in the resonant network 140. When current flows into the second energy storage unit, charges are accumulated and an electric field is formed, thereby storing energy. When the current changes, the stored electric energy is released, thereby affecting the behavior of the resonant network 140.

[0065] In the embodiment of the present invention, the first frequency modulation unit, the first energy storage unit and the second energy storage unit jointly determine the resonant frequency of the resonant network 140. By adjusting the parameters of the components in the first frequency modulation unit, the first energy storage unit and the second energy storage unit, the resonant frequency can be flexibly controlled.

[0066] Optionally, based on the above embodiments, continue to refer to Figure 2 The first frequency modulation unit includes a first inductor L21, and the first inductor L21 is connected to the input interface V DCand the center tap 112 of the primary coil 111; the first energy storage unit includes a first capacitor C21, and the first capacitor C21 is connected between the first end and the second end of the first switch module 120; the second energy storage unit includes a second capacitor C22, and the second capacitor C22 is connected between the first end and the second end of the second switch module 130.

[0067] Specifically, the first inductor L21 refers to the inductor element in the first frequency modulation unit, which is responsible for storing and releasing energy when current flows, thereby affecting the frequency characteristics of the resonant network 140. When current flows through the first inductor L21, a magnetic field is generated around it. According to Faraday's law of electromagnetic induction, the inductor generates a reverse voltage to the current change, affecting the flow of current. Under the interaction with the first capacitor C21 and the second capacitor C22, the alternating charging and discharging of the first inductor L21 and the capacitor forms a resonance, so that the circuit can operate efficiently at a specific frequency.

[0068] The first capacitor C21 refers to the capacitive element in the first energy storage unit, which is responsible for storing electrical energy in the electric field and releasing the stored energy when the current changes. When current flows through the first capacitor C21, the capacitor is charged; when the circuit needs energy, the first capacitor C21 will discharge to provide the required electrical energy. This process alternates with the energy storage and release of the first inductor L21 to form a resonance.

[0069] The second capacitor C22 refers to the capacitor element in the second energy storage unit, which is responsible for storing electrical energy in the electric field and releasing the stored energy when the current changes. When current flows through the second capacitor C22, the capacitor is charged; when the circuit needs energy, the second capacitor C22 will discharge to provide the required electrical energy. This process alternates with the energy storage and release of the first inductor L21 to form a resonance.

[0070] In the embodiment of the present invention, the energy stored in the first inductor L21 forms a magnetic field in the inductor, and the first capacitor C21 and the second capacitor C22 store electric energy in the electric field. The current and voltage alternate between the inductor and the capacitor to form a periodic oscillation. The resonant frequency is determined by the following formula:

[0071]

[0072] Wherein, f is the resonant frequency; L is the inductance of the first inductor L21; and C is the equivalent capacitance, that is, the equivalent capacitance of the first capacitor C21 and the second capacitor C22.

[0073] The technical solution of the embodiment of the present invention, through the alternating storage and release of energy in the inductor and the capacitor, jointly constitutes a resonant network 140, thereby realizing soft switching of the push-pull inverter circuit, so that the switching device can be turned off when the voltage is zero, effectively reducing the transient voltage and current spikes during the switching process of the switch module, and improving the overall energy conversion efficiency of the push-pull inverter circuit.

[0074] Figure 5 FIG. 1 is another schematic diagram of a push-pull inverter circuit provided by an embodiment of the present invention. Figure 5 As shown, optionally, the resonant network 140 may further include: a second frequency modulation unit, the second frequency modulation unit is connected between the secondary coil 113 and the load 150, and the second frequency modulation unit is used to form resonance with the first frequency modulation unit, the first energy storage unit and the second energy storage unit.

[0075] The second frequency modulation unit refers to another unit in the resonant network 140 for adjusting the resonant frequency. When current flows through the second frequency modulation unit, a magnetic field is generated and energy is stored. This energy can be released when the current changes, thereby affecting the working state of the circuit.

[0076] Optionally, based on the above embodiment, continue to refer to Figure 5 The second frequency modulation unit may include: a second inductor L22, the second inductor L22 is connected between the secondary coil 113 and the load 150, and the second inductor L22 is used to form resonance with the first inductor L21, the first capacitor C21 and the second capacitor C22.

[0077] Specifically, the second inductor L22 refers to the inductor element in the second frequency modulation unit, which is responsible for storing and releasing energy when current flows, thereby affecting the frequency characteristics of the resonant network 140. When current flows through the second inductor L22, a magnetic field is generated around it. According to Faraday's law of electromagnetic induction, the inductor generates a reverse voltage to the current change, affecting the flow of current. Under the interaction with the first capacitor C21 and the second capacitor C22, the first inductor L21 and the second inductor L22 form a resonance with the alternating charge and discharge of the capacitor, so that the circuit can operate efficiently at a specific frequency.

[0078] In the embodiment of the present invention, adding the second inductor L22 in the secondary coil 113 can smooth the current flowing to the load 150 , reduce the current pulsation, and protect the safety of the push-pull inverter circuit and the load 150 .

[0079] The energy stored in the first inductor L21 and the second inductor L22 forms a magnetic field in the inductor, and the first capacitor C21 and the second capacitor C22 store electric energy in the electric field. The current and voltage alternate between the inductor and the capacitor to form a periodic oscillation. The resonant frequency is determined by the following formula:

[0080]

[0081] Among them, f1 is the generated resonant frequency; L1 is the equivalent inductance, that is, the equivalent inductance of the first inductor L21 and the second inductor L22; C is the equivalent capacitance, that is, the equivalent capacitance of the first capacitor C21 and the second capacitor C22.

[0082] The technical solution of the embodiment of the present invention, through the alternating storage and release of energy in the inductor and the capacitor, jointly constitutes a resonant network 140, thereby realizing soft switching of the push-pull inverter circuit, so that the switching device can be turned off when the voltage is zero, effectively reducing the transient voltage and current spikes during the switching process of the switch module, and improving the overall energy conversion efficiency of the push-pull inverter circuit.

[0083] Optionally, based on the above embodiments, continue to refer to Figure 5 The push-pull inverter circuit further includes: a third energy storage module 170, the third energy storage module 170 is connected to the input interface V DC and the ground terminal, the third energy storage module 170 is used to connect the input interface V DC The input DC signal is temporarily stored.

[0084] The third energy storage module 170 refers to an electronic component that stores electrical energy during the switching of the switch module to ensure the stability of the power supply when the switch state changes. The third energy storage module 170 can play a buffering role during the switch operation, avoid the impact of instantaneous current changes on the circuit, and improve the reliability of the system.

[0085] Optionally, based on the above embodiments, continue to refer to Figure 5 The third energy storage module 170 includes: a third capacitor C23, the third capacitor C23 is connected to the input interface V DC and the ground terminal, the third capacitor C23 is used to connect the input interface V DC The input DC signal is temporarily stored.

[0086] Specifically, the third capacitor C23 is connected to the input interface V DC The capacitor between the first switch module 120 and the ground terminal is mainly used to temporarily store the input interface V when the first switch module 120 and the second switch module 130 perform switching actions. DC Input DC signal. When the input interface V DCWhen a DC signal is provided, the third capacitor C23 will be charged to store the input electric energy and be ready to release it when needed. When the first switch module 120 and the second switch module 130 perform switching actions, the third capacitor C23 will release the stored electric energy to ensure that the voltage and current of the push-pull inverter circuit remain stable during the switching process.

[0087] The technical solution of the embodiment of the present invention smoothes the fluctuation of the input voltage through the third capacitor C23, reduces the transient current change during the switching process, thereby reducing the switching loss and improving the energy efficiency of the overall system.

[0088] An embodiment of the present invention further provides a high-frequency power supply device, comprising: the push-pull inverter circuit provided by any of the above embodiments, which can perform the functions of the corresponding push-pull inverter circuit and have corresponding beneficial effects.

[0089] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A push-pull inverter circuit, characterized in that: include: Input interface, used for inputting direct current signal; A transformer module, wherein the center tap of the primary coil of the transformer module is connected to the input interface, and the secondary coil of the transformer module is used to connect to a load; The first switch module is connected between the first end of the primary coil and the ground end, and the control end of the first switch module is used to input a first control signal; The second switch module is connected between the second end of the primary coil and the ground end, and the control end of the second switch module is used to input a second control signal; A resonant network, wherein the resonant network is connected to the primary coil and the first switch module and the second switch module, and the resonant network is used to adjust the first switch module to soft switch according to the first control signal; and to adjust the second switch module to soft switch according to the second control signal.

2. The push-pull inverter circuit according to claim 1, characterized in that: The first end of the resonant network is connected to the input interface, the second end of the resonant network is connected to the center tap, the third end of the resonant network is connected to the first end of the first switch module, and the fourth end of the resonant network is connected to the second end of the first switch module; the fifth end of the resonant network is connected to the first end of the second switch module, and the sixth end of the resonant network is connected to the second end of the second switch module; The resonant network is used to adjust the first switch module to be turned on according to the first control signal when the voltage between the second end and the first end is zero; and to adjust the second switch module to be turned on according to the second control signal when the voltage between the second end and the first end is zero.

3. The push-pull inverter circuit according to claim 1, characterized in that: The first switch module includes a first gallium nitride switch tube; The second switch module includes a second gallium nitride switch tube; The resonant network is used to adjust the first gallium nitride switch tube to be turned on according to the first control signal when the voltage between the drain and the source is zero; and to adjust the second gallium nitride switch tube to be turned on according to the second control signal when the voltage between the drain and the source is zero.

4. The push-pull inverter circuit according to any one of claims 1 to 3, characterized in that: The resonant network comprises: A first frequency modulation unit, wherein the first frequency modulation unit is connected between the input interface and the center tap of the primary coil; A first energy storage unit, wherein the first energy storage unit is connected between the first end and the second end of the first switch module; A second energy storage unit, wherein the second energy storage unit is connected between the first end and the second end of the second switch module.

5. The push-pull inverter circuit according to claim 4, characterized in that: The first frequency modulation unit includes a first inductor, and the first inductor is connected between the input interface and the center tap of the primary coil; The first energy storage unit includes a first capacitor, and the first capacitor is connected between the first end and the second end of the first switch module; The second energy storage unit includes a second capacitor connected between the first end and the second end of the second switch module.

6. The push-pull inverter circuit according to claim 5, characterized in that: The resonant network further comprises: A second frequency modulation unit, wherein the second frequency modulation unit is connected between the secondary coil and the load, and the second frequency modulation unit is used to form resonance with the first frequency modulation unit, the first energy storage unit and the second energy storage unit.

7. The push-pull inverter circuit according to claim 6, characterized in that: The second frequency modulation unit comprises: A second inductor is connected between the secondary coil and the load, and is used to form resonance with the first inductor, the first capacitor and the second capacitor.

8. The push-pull inverter circuit according to any one of claims 1 to 3, characterized in that: The push-pull inverter circuit further includes: A third energy storage module, wherein the third energy storage module is connected between the input interface and the ground terminal, and is used for temporarily storing the DC signal input from the input interface when the first switch module and the second switch module perform a switching action.

9. The push-pull inverter circuit according to claim 8, characterized in that: The third energy storage module comprises: A third capacitor is connected between the input interface and the ground terminal, and is used to temporarily store the DC signal input from the input interface each time the first switch module and the second switch module perform a switching action.

10. A high frequency power supply device, characterized in that: include: The push-pull inverter circuit according to any one of claims 1 to 9.

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