A buck-boost circuit oscillation suppression method and system based on switch tube conduction control

Abstract

The application provides a Buck-Boost circuit oscillation suppression method and system based on switching tube conduction control in the field of power electronics, and the method comprises the following steps: step S1, the inductor current flowing through the inductor L1 in the Buck-Boost circuit is detected in real time through a current sensor, and a current discontinuous signal indicating that the inductor current enters a discontinuous mode is generated; step S2, based on the current discontinuous signal, an additional driving signal for a specific power switching tube is generated to control the specific power switching tube to enter a conduction state; step S3, a damping path is provided for the resonance circuit composed of the inductor L1 and the capacitor through the conduction power switching tube, so as to absorb the oscillation energy. The application has the advantages that high-efficiency and low-loss oscillation suppression is realized, and the continuous energy loss and heat dissipation burden caused by the traditional passive absorption circuit are avoided.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a method and system for suppressing oscillations in a Buck-Boost circuit based on switch conduction control. Background Technology

[0002] The unidirectional four-switch Buck-Boost circuit is often used in power supply systems with a wide input voltage range due to its ability to perform boost and buck conversion and its flexible operating modes. This circuit typically contains four power switches, and by employing different control logic combinations for each switch, Buck, Boost, and Buck-Boost operating modes can be implemented respectively.

[0003] In practical applications, to achieve faster dynamic response or reduce inductor size at specific power levels, this circuit sometimes operates in discontinuous current mode. However, in this mode, when the inductor current drops to zero, the inductor in the circuit forms a high-order resonant circuit with the junction capacitance of the power switch or the equivalent parasitic capacitance in the circuit, thereby inducing high-frequency oscillations. Such oscillations can have several adverse effects, such as causing ripple and noise in the circuit's output voltage, increasing electromagnetic interference in the system, and potentially causing overvoltage stress on the switch, threatening the stability of circuit operation.

[0004] To suppress the aforementioned oscillations, passive absorption circuits are commonly used in existing technologies. The most typical example is an RCD absorption network consisting of resistors, capacitors, and diodes connected in parallel at the critical nodes of the resonant circuit. This network achieves a damping effect by providing a release path for the oscillation energy. However, this traditional RCD absorption method has the following inherent drawbacks: First, its absorption mechanism involves continuous energy dissipation through the resistor. Regardless of the oscillation energy, as long as the circuit operates in discontinuous mode, power dissipation will occur in the resistor. This not only leads to additional energy loss and reduces system efficiency but also causes the resistor element to continuously heat up. Second, to address this heat generation issue, appropriate heat dissipation measures are required, which undoubtedly increases the system size, cost, and thermal design complexity, limiting the improvement of power density. Furthermore, the response speed and damping effect of this passive absorption circuit are fixed, making it difficult to achieve optimal adaptive suppression.

[0005] Therefore, how to provide a Buck-Boost circuit oscillation suppression method and system based on switch conduction control to achieve high-efficiency, low-loss oscillation suppression and avoid the continuous energy loss and heat dissipation burden caused by traditional passive absorption circuits has become an urgent technical problem to be solved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a Buck-Boost circuit oscillation suppression method and system based on switch conduction control, so as to achieve high-efficiency and low-loss oscillation suppression and avoid the continuous energy loss and heat dissipation burden caused by traditional passive absorption circuits.

[0007] In a first aspect, the present invention provides a method for suppressing oscillations in a Buck-Boost circuit based on switch-transistor turn-on control, comprising the following steps: Step S1: Detect the inductor current flowing through inductor L1 in the Buck-Boost circuit in real time using a current sensor, and generate a current discontinuity signal indicating that the inductor current has entered the discontinuous mode. Step S2: Based on the current discontinuous signal, generate an additional drive signal for a specific power switch to control the specific power switch to enter the conduction state. Step S3: By using the conducting power switch, a damping path is provided for the resonant circuit formed by inductor L1 and capacitor bank to absorb oscillation energy.

[0008] Furthermore, step S1 specifically includes: A current threshold is set, which is 0 or a negative value close to 0; the inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and the inductor current is compared with the current threshold. When the inductor current is less than the current threshold, it is determined that the inductor current has entered the discontinuous mode, and a discontinuous current signal is generated.

[0009] Furthermore, in step S2, the specific power switch refers to the power switch that acts as a high-frequency switch when the Buck-Boost circuit is in Buck operating mode, Boost operating mode, or Buck-Boost operating mode.

[0010] Furthermore, in step S2, the process of generating the additional driving signal specifically includes: After receiving the discontinuous current signal, a preset delay time is applied, and after the delay time, a pulse signal with a predetermined width is generated as an additional driving signal.

[0011] Furthermore, the setting of the delay time, based on the oscillation period of the resonant circuit, is used to avoid signal noise near the current zero-crossing point and to ensure that a specific power switch is triggered to conduct near the peak of the oscillation voltage or oscillation current. The predetermined width setting ensures that the conduction time of a specific power switch is sufficient to dampen the oscillating current, but is much shorter than the main power switching cycle of the Buck-Boost circuit.

[0012] Secondly, the present invention provides a Buck-Boost circuit oscillation suppression system based on switch conduction control, comprising the following modules: The current discontinuous signal generation module is used to detect the inductor current flowing through inductor L1 in the Buck-Boost circuit in real time through a current sensor, and generate a current discontinuity signal indicating that the inductor current enters the discontinuous mode. An additional drive signal generation module is used to generate an additional drive signal for a specific power switch based on the current discontinuous signal, so as to control the specific power switch to enter the conduction state. The oscillation suppression module is used to provide a damping path for the resonant circuit formed by inductor L1 and capacitor bank through the conducting power switch to absorb oscillation energy.

[0013] Furthermore, the current discontinuous signal generation module is specifically used for: A current threshold is set, which is 0 or a negative value close to 0; the inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and the inductor current is compared with the current threshold. When the inductor current is less than the current threshold, it is determined that the inductor current has entered the discontinuous mode, and a discontinuous current signal is generated.

[0014] Furthermore, in the additional drive signal generation module, the specific power switch refers to the power switch that acts as a high-frequency switch when the Buck-Boost circuit is in Buck operating mode, Boost operating mode, or Buck-Boost operating mode.

[0015] Furthermore, in the additional drive signal generation module, the generation process of the additional drive signal is specifically as follows: After receiving the discontinuous current signal, a preset delay time is applied, and after the delay time, a pulse signal with a predetermined width is generated as an additional driving signal.

[0016] Furthermore, the setting of the delay time, based on the oscillation period of the resonant circuit, is used to avoid signal noise near the current zero-crossing point and to ensure that a specific power switch is triggered to conduct near the peak of the oscillation voltage or oscillation current. The predetermined width setting ensures that the conduction time of a specific power switch is sufficient to dampen the oscillating current, but is much shorter than the main power switching cycle of the Buck-Boost circuit.

[0017] The advantages of this invention are: 1. The inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and a discontinuous current signal indicating that the inductor current has entered discontinuous mode is generated. Based on the discontinuous current signal, an additional drive signal is generated for a specific power switch to control the specific power switch to enter the conduction state. The conducting power switch provides a damping path for the resonant circuit formed by inductor L1 and capacitor bank to absorb oscillation energy. That is, by detecting the moment when the inductor current enters discontinuous mode in real time as a trigger signal, a brief and precise additional drive signal is generated to control the original power switch in the circuit to turn on instantaneously near the peak of the oscillation voltage or oscillation current. This active control behavior uses the on-resistance of the power switch itself to provide a damping path for the resonant circuit, efficiently absorbing oscillation energy with minimal conduction time, thereby achieving "on-demand" suppression instead of the "continuous" dissipation of traditional passive absorption circuits. This fundamentally avoids continuous energy loss and the resulting heat dissipation burden, ultimately achieving high-efficiency, low-loss oscillation suppression and avoiding the continuous energy loss and heat dissipation burden caused by traditional passive absorption circuits.

[0018] 2. By detecting the inductor current entering discontinuous mode in real time and generating a discontinuous current signal, a specific power switch is controlled to turn on, providing a low-impedance damping path for the resonant circuit formed by the inductor and capacitor. This active damping mechanism directly absorbs oscillation energy, thereby significantly suppressing the inherent oscillation phenomenon of the Buck-Boost circuit in discontinuous mode, avoiding voltage and current fluctuations caused by oscillation, enhancing the steady-state and transient stability of the circuit, and solving the problem of limited effectiveness or introduction of additional losses in traditional passive damping methods.

[0019] 3. Since oscillations can cause additional circulating current losses and switching losses, suppressing oscillations reduces these unnecessary energy dissipations. Especially in light load or intermittent operating modes, oscillation suppression can effectively improve the conversion efficiency of the circuit and reduce overall power consumption. This is of great significance for battery-powered devices or high-energy-efficiency application scenarios, as it helps to extend the device's battery life and reduce thermal management requirements.

[0020] 4. High-frequency noise generated by oscillation is the main source of electromagnetic interference. Damped oscillation significantly reduces the radiation and conduction of high-frequency noise during circuit operation, which helps the circuit to meet electromagnetic compatibility (EMC) standards more easily, reduces interference to surrounding electronic equipment, improves product reliability and market access, and may also simplify filter circuit design and reduce costs.

[0021] 5. Oscillations can cause power switching transistors, inductors, capacitors and other components to be subjected to overvoltage or overcurrent stress, which can accelerate their aging or even damage them. By actively suppressing oscillations, these electrical stresses are reduced, thereby protecting key power components, extending the service life of the overall system, improving reliability in harsh working environments, and reducing maintenance needs and failure rates.

[0022] 6. Based on the oscillation period, the delay time and pulse width settings are used to avoid detection noise near the current zero crossing point and ensure that the switching transistor is triggered to conduct near the oscillation peak. The pulse width provides sufficient damping but is much smaller than the main switching period. This optimized control achieves efficient damping, avoids false triggering or over-conduction, improves response accuracy, and adapts to different working conditions, thus enhancing the robustness and practicality of the method.

[0023] 7. Applicable to various operating modes such as Buck, Boost, and Buck-Boost, it achieves oscillation suppression for various DC-DC topologies by controlling the high-frequency switching transistors (such as the power transistor acting as the main switch) in the corresponding mode. This versatility allows for flexible integration into various power management systems, reducing development and production complexity and expanding application scenarios.

[0024] 8. By utilizing existing current sensors and drive circuits, additional drive signals can be generated simply by adding control logic (such as comparators, delay circuits, and pulse generators). This eliminates the need for expensive additional passive damping components (such as resistors or buffer circuits), reducing hardware costs and size. It is also easy to upgrade or integrate into existing designs, making it highly economical and feasible.

[0025] 9. By suppressing oscillations, the transient response of the circuit during load changes or mode switching is smoother, reducing overshoot and ringing of output voltage or current, and improving the dynamic regulation performance and stability of the system. This is especially important for applications requiring fast response and precise regulation (such as communication equipment or industrial control), and helps to improve the overall power quality. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Figure 1 This is a flowchart of a Buck-Boost circuit oscillation suppression method based on switch conduction control according to the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of a Buck-Boost circuit oscillation suppression system based on switch conduction control according to the present invention.

[0029] Figure 3 This is a circuit diagram of the Buck-Boost circuit of the present invention. Detailed Implementation

[0030] The technical solution in this application embodiment has the following general idea: by using the moment when the inductor current enters the discontinuous mode in real time as a trigger signal, a brief and precise additional drive signal is generated to control the original power switch in the control circuit to turn on instantaneously near the peak value of the oscillation voltage or oscillation current; this active control behavior uses the on-resistance of the power switch itself to provide a damping path for the resonant circuit, so as to efficiently absorb the oscillation energy with minimal on-time, thereby achieving "on-demand" suppression rather than the "continuous" dissipation of traditional passive absorption circuits, fundamentally avoiding continuous energy loss and the resulting heat dissipation burden.

[0031] Please refer to Figures 1 to 3 As shown, the Buck-Boost circuit used in this invention includes four power switching transistors (Q1, Q2, D1, D2), a capacitor bank (C1, C2, C3, C4, C5), an inductor L1, an inductor Load, and a resistor R1. Capacitor C1 is connected in parallel across MOSFET Q1; capacitor C2 is connected in parallel across diode D1; capacitor C3 is connected in parallel across diode D2; capacitor C4 is connected in parallel across MOSFET Q2; one end of inductor L1 is connected to one end of capacitor C1 and one end of capacitor C2, and the other end is connected to one end of capacitor C3 and one end of capacitor C4; resistor R1 is connected in series with capacitor C5, and then in parallel with inductor Load, with one end connected to the other end of capacitor C3 and the other end connected to the other end of capacitor C4.

[0032] A preferred embodiment of the Buck-Boost circuit oscillation suppression method based on switch conduction control of the present invention includes the following steps: Step S1: Detect the inductor current flowing through inductor L1 in the Buck-Boost circuit in real time using a current sensor, and generate a current discontinuity signal indicating that the inductor current has entered the discontinuous mode. Step S2: Based on the current discontinuous signal, generate an additional drive signal for a specific power switch to control the specific power switch to enter the conduction state. Step S3: By using the conducting power switch, a damping path is provided for the resonant circuit formed by inductor L1 and capacitor bank to absorb oscillation energy.

[0033] Step S1 specifically involves: A current threshold is set, which is 0 or a negative value close to 0; the inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and the inductor current is compared with the current threshold. When the inductor current is less than the current threshold, it is determined that the inductor current has entered the discontinuous mode, and a discontinuous current signal is generated.

[0034] A current sensor (such as a Hall sensor or a sampling resistor) monitors the current of inductor L1 in real time. A current threshold is set to 0 or a slightly negative value (e.g., -0.1A) to handle noise interference. When the inductor current falls below the current threshold, the comparator outputs a high level as a current discontinuity signal. In practical circuits, a filter circuit (such as an RC low-pass filter) can be added to smooth the signal and prevent false triggering. The current threshold setting needs to be adjusted according to the circuit's operating conditions. For example, in light-load mode, the threshold can be set to 0A; while during heavy-load switching, it can be set to a slightly negative value to detect discontinuity points earlier, which improves the robustness of the detection.

[0035] In step S2, the specific power switch refers to the power switch that acts as a high-frequency switch when the Buck-Boost circuit is in Buck operating mode, Boost operating mode, or Buck-Boost operating mode.

[0036] In step S2, the process of generating the additional driving signal is as follows: After receiving the discontinuous current signal, a preset delay time is applied, and after the delay time, a pulse signal with a predetermined width is generated as an additional driving signal.

[0037] The delay time setting, based on the oscillation period of the resonant circuit, is used to avoid signal noise near the current zero-crossing point and to ensure that a specific power switch is triggered to turn on near the peak of the oscillation voltage or oscillation current. The predetermined width setting ensures that the conduction time of a specific power switch is sufficient to dampen the oscillating current, but is much shorter than the main power switching cycle of the Buck-Boost circuit.

[0038] Based on the discontinuous current signal, an additional drive signal generation module (such as a programmable delay unit) introduces a delay time (Td) and a pulse width (Tw). The delay time Td is usually set to 1 / 4 to 1 / 2 of the resonant period (Tr) (e.g., when Tr=1μs, Td=0.25μs) to avoid noise at the current zero-crossing point and to trigger the switching transistor near the oscillation peak. The pulse width Tw should be much smaller than the main switching period (e.g., when the main period is 10μs, Tw=0.1μs) to ensure sufficient damping while minimizing losses.

[0039] The delay time and pulse width can be calibrated experimentally or dynamically adjusted according to the oscillation frequency using an adaptive algorithm. For example, in Buck mode, power switch Q1 or Q2 is triggered; in Boost mode, it is the active switch corresponding to D1 or D2. This adaptive design enhances versatility.

[0040] A preferred embodiment of the Buck-Boost circuit oscillation suppression system based on switch conduction control of the present invention includes the following modules: The current discontinuous signal generation module is used to detect the inductor current flowing through inductor L1 in the Buck-Boost circuit in real time through a current sensor, and generate a current discontinuity signal indicating that the inductor current enters the discontinuous mode. An additional drive signal generation module is used to generate an additional drive signal for a specific power switch based on the current discontinuous signal, so as to control the specific power switch to enter the conduction state. The oscillation suppression module is used to provide a damping path for the resonant circuit formed by inductor L1 and capacitor bank through the conducting power switch to absorb oscillation energy.

[0041] The discontinuous current signal generation module is specifically used for: A current threshold is set, which is 0 or a negative value close to 0; the inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and the inductor current is compared with the current threshold. When the inductor current is less than the current threshold, it is determined that the inductor current has entered the discontinuous mode, and a discontinuous current signal is generated.

[0042] A current sensor (such as a Hall sensor or a sampling resistor) monitors the current of inductor L1 in real time. A current threshold is set to 0 or a slightly negative value (e.g., -0.1A) to handle noise interference. When the inductor current falls below the current threshold, the comparator outputs a high level as a current discontinuity signal. In practical circuits, a filter circuit (such as an RC low-pass filter) can be added to smooth the signal and prevent false triggering. The current threshold setting needs to be adjusted according to the circuit's operating conditions. For example, in light-load mode, the threshold can be set to 0A; while during heavy-load switching, it can be set to a slightly negative value to detect discontinuity points earlier, which improves the robustness of the detection.

[0043] In the additional drive signal generation module, the specific power switch refers to the power switch that acts as a high-frequency switch when the Buck-Boost circuit is in Buck operating mode, Boost operating mode, or Buck-Boost operating mode.

[0044] In the additional drive signal generation module, the generation process of the additional drive signal is specifically as follows: After receiving the discontinuous current signal, a preset delay time is applied, and after the delay time, a pulse signal with a predetermined width is generated as an additional driving signal.

[0045] The delay time setting, based on the oscillation period of the resonant circuit, is used to avoid signal noise near the current zero-crossing point and to ensure that a specific power switch is triggered to turn on near the peak of the oscillation voltage or oscillation current. The predetermined width setting ensures that the conduction time of a specific power switch is sufficient to dampen the oscillating current, but is much shorter than the main power switching cycle of the Buck-Boost circuit.

[0046] Based on the discontinuous current signal, an additional drive signal generation module (such as a programmable delay unit) introduces a delay time (Td) and a pulse width (Tw). The delay time Td is usually set to 1 / 4 to 1 / 2 of the resonant period (Tr) (e.g., when Tr=1μs, Td=0.25μs) to avoid noise at the current zero-crossing point and to trigger the switching transistor near the oscillation peak. The pulse width Tw should be much smaller than the main switching period (e.g., when the main period is 10μs, Tw=0.1μs) to ensure sufficient damping while minimizing losses.

[0047] The delay time and pulse width can be calibrated experimentally or dynamically adjusted according to the oscillation frequency using an adaptive algorithm. For example, in Buck mode, power switch Q1 or Q2 is triggered; in Boost mode, it is the active switch corresponding to D1 or D2. This adaptive design enhances versatility.

[0048] In summary, the advantages of this invention are as follows: 1. The inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and a discontinuous current signal indicating that the inductor current has entered discontinuous mode is generated. Based on the discontinuous current signal, an additional drive signal is generated for a specific power switch to control the specific power switch to enter the conduction state. The conducting power switch provides a damping path for the resonant circuit formed by inductor L1 and capacitor bank to absorb oscillation energy. That is, by detecting the moment when the inductor current enters discontinuous mode in real time as a trigger signal, a brief and precise additional drive signal is generated to control the original power switch in the circuit to turn on instantaneously near the peak of the oscillation voltage or oscillation current. This active control behavior uses the on-resistance of the power switch itself to provide a damping path for the resonant circuit, efficiently absorbing oscillation energy with minimal conduction time, thereby achieving "on-demand" suppression instead of the "continuous" dissipation of traditional passive absorption circuits. This fundamentally avoids continuous energy loss and the resulting heat dissipation burden, ultimately achieving high-efficiency, low-loss oscillation suppression and avoiding the continuous energy loss and heat dissipation burden caused by traditional passive absorption circuits.

[0049] 2. By detecting the inductor current entering discontinuous mode in real time and generating a discontinuous current signal, a specific power switch is controlled to turn on, providing a low-impedance damping path for the resonant circuit formed by the inductor and capacitor. This active damping mechanism directly absorbs oscillation energy, thereby significantly suppressing the inherent oscillation phenomenon of the Buck-Boost circuit in discontinuous mode, avoiding voltage and current fluctuations caused by oscillation, enhancing the steady-state and transient stability of the circuit, and solving the problem of limited effectiveness or introduction of additional losses in traditional passive damping methods.

[0050] 3. Since oscillations can cause additional circulating current losses and switching losses, suppressing oscillations reduces these unnecessary energy dissipations. Especially in light load or intermittent operating modes, oscillation suppression can effectively improve the conversion efficiency of the circuit and reduce overall power consumption. This is of great significance for battery-powered devices or high-energy-efficiency application scenarios, as it helps to extend the device's battery life and reduce thermal management requirements.

[0051] 4. High-frequency noise generated by oscillation is the main source of electromagnetic interference. Damped oscillation significantly reduces the radiation and conduction of high-frequency noise during circuit operation, which helps the circuit to meet electromagnetic compatibility (EMC) standards more easily, reduces interference to surrounding electronic equipment, improves product reliability and market access, and may also simplify filter circuit design and reduce costs.

[0052] 5. Oscillations can cause power switching transistors, inductors, capacitors and other components to be subjected to overvoltage or overcurrent stress, which can accelerate their aging or even damage them. By actively suppressing oscillations, these electrical stresses are reduced, thereby protecting key power components, extending the service life of the overall system, improving reliability in harsh working environments, and reducing maintenance needs and failure rates.

[0053] 6. Based on the oscillation period, the delay time and pulse width settings are used to avoid detection noise near the current zero crossing point and ensure that the switching transistor is triggered to conduct near the oscillation peak. The pulse width provides sufficient damping but is much smaller than the main switching period. This optimized control achieves efficient damping, avoids false triggering or over-conduction, improves response accuracy, and adapts to different working conditions, thus enhancing the robustness and practicality of the method.

[0054] 7. Applicable to various operating modes such as Buck, Boost, and Buck-Boost, it achieves oscillation suppression for various DC-DC topologies by controlling the high-frequency switching transistors (such as the power transistor acting as the main switch) in the corresponding mode. This versatility allows for flexible integration into various power management systems, reducing development and production complexity and expanding application scenarios.

[0055] 8. By utilizing existing current sensors and drive circuits, additional drive signals can be generated simply by adding control logic (such as comparators, delay circuits, and pulse generators). This eliminates the need for expensive additional passive damping components (such as resistors or buffer circuits), reducing hardware costs and size. It is also easy to upgrade or integrate into existing designs, making it highly economical and feasible.

[0056] 9. By suppressing oscillations, the transient response of the circuit during load changes or mode switching is smoother, reducing overshoot and ringing of output voltage or current, and improving the dynamic regulation performance and stability of the system. This is especially important for applications requiring fast response and precise regulation (such as communication equipment or industrial control), and helps to improve the overall power quality.

[0057] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for suppressing oscillations in a Buck-Boost circuit based on switch-transistor conduction control, characterized in that: Includes the following steps: Step S1: Detect the inductor current flowing through inductor L1 in the Buck-Boost circuit in real time using a current sensor, and generate a current discontinuity signal indicating that the inductor current has entered the discontinuous mode. Step S2: Based on the current discontinuous signal, generate an additional drive signal for a specific power switch to control the specific power switch to enter the conduction state. Step S3: By using the conducting power switch, a damping path is provided for the resonant circuit formed by inductor L1 and capacitor bank to absorb oscillation energy.

2. The Buck-Boost circuit oscillation suppression method based on switch conduction control as described in claim 1, characterized in that: Step S1 specifically involves: A current threshold is set, which is 0 or a negative value close to 0; the inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and the inductor current is compared with the current threshold. When the inductor current is less than the current threshold, it is determined that the inductor current has entered the discontinuous mode, and a discontinuous current signal is generated.

3. The Buck-Boost circuit oscillation suppression method based on switch conduction control as described in claim 1, characterized in that: In step S2, the specific power switch refers to the power switch that acts as a high-frequency switch when the Buck-Boost circuit is in Buck operating mode, Boost operating mode, or Buck-Boost operating mode.

4. The Buck-Boost circuit oscillation suppression method based on switch conduction control as described in claim 1, characterized in that: In step S2, the process of generating the additional driving signal is as follows: After receiving the discontinuous current signal, a preset delay time is applied, and after the delay time, a pulse signal with a predetermined width is generated as an additional driving signal.

5. The Buck-Boost circuit oscillation suppression method based on switch conduction control as described in claim 4, characterized in that: The delay time setting, based on the oscillation period of the resonant circuit, is used to avoid signal noise near the current zero-crossing point and to ensure that a specific power switch is triggered to turn on near the peak of the oscillation voltage or oscillation current. The predetermined width setting ensures that the conduction time of a specific power switch is sufficient to dampen the oscillating current, but is much shorter than the main power switching cycle of the Buck-Boost circuit.

6. A Buck-Boost circuit oscillation suppression system based on switch conduction control, characterized in that: Includes the following modules: The current discontinuous signal generation module is used to detect the inductor current flowing through inductor L1 in the Buck-Boost circuit in real time through a current sensor, and generate a current discontinuity signal indicating that the inductor current enters the discontinuous mode. An additional drive signal generation module is used to generate an additional drive signal for a specific power switch based on the current discontinuous signal, so as to control the specific power switch to enter the conduction state. The oscillation suppression module is used to provide a damping path for the resonant circuit formed by inductor L1 and capacitor bank through the conducting power switch to absorb oscillation energy.

7. The Buck-Boost circuit oscillation suppression system based on switch conduction control as described in claim 6, characterized in that: The discontinuous current signal generation module is specifically used for: A current threshold is set, which is 0 or a negative value close to 0; the inductor current flowing through inductor L1 in the Buck-Boost circuit is detected in real time by a current sensor, and the inductor current is compared with the current threshold. When the inductor current is less than the current threshold, it is determined that the inductor current has entered the discontinuous mode, and a discontinuous current signal is generated.

8. The Buck-Boost circuit oscillation suppression system based on switch conduction control as described in claim 6, characterized in that: In the additional drive signal generation module, the specific power switch refers to the power switch that acts as a high-frequency switch when the Buck-Boost circuit is in Buck operating mode, Boost operating mode, or Buck-Boost operating mode.

9. The Buck-Boost circuit oscillation suppression system based on switch conduction control as described in claim 6, characterized in that: In the additional drive signal generation module, the generation process of the additional drive signal is specifically as follows: After receiving the discontinuous current signal, a preset delay time is applied, and after the delay time, a pulse signal with a predetermined width is generated as an additional driving signal.

10. The Buck-Boost circuit oscillation suppression system based on switch conduction control as described in claim 9, characterized in that: The delay time setting, based on the oscillation period of the resonant circuit, is used to avoid signal noise near the current zero-crossing point and to ensure that a specific power switch is triggered to turn on near the peak of the oscillation voltage or oscillation current. The predetermined width setting ensures that the conduction time of a specific power switch is sufficient to dampen the oscillating current, but is much shorter than the main power switching cycle of the Buck-Boost circuit.

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