Current sampling system of high-frequency switching converter

Abstract

The invention provides a current sampling system of a high-frequency switch converter, which relates to the technical field of high-frequency switch converters and comprises a switch unit, a duplex winding coupling inductor, a current sensor, a voltage dividing unit and a control unit, the first output end of the switch unit is connected with the first dotted terminal of the duplex-winding coupling inductor, the second output end of the switch unit is connected with the second dotted terminal of the duplex-winding coupling inductor, and the first end of the voltage dividing unit is connected with the first synonym terminal and the second synonym terminal of the duplex-winding coupling inductor. The second end of the voltage dividing unit is connected with the negative electrode of the power supply, the third end of the voltage dividing power supply is connected with the first input end of the control unit, the second input end of the control unit is connected with the first synonym end or the second synonym end of the duplex winding coupling inductor through the current sensor, and the output end of the control unit is connected with the control end of the switch unit. The integration level of the high-frequency switching converter can be improved.

Description

Technical Field

[0001] This invention relates to the field of high-frequency switching converter technology, and more specifically, to a current sampling system for a high-frequency switching converter. Background Technology

[0002] High-frequency switching converters, as core power conversion devices in the field of power electronics, are widely used in many fields such as new energy vehicles (e.g., motor drive systems, battery management systems), photovoltaic and wind power generation (grid-connected inverters), industrial automation (precision power supply), and consumer electronics (fast charging for mobile phones, power supplies for laptops). They achieve efficient conversion of electrical energy through high-frequency switching action.

[0003] In related technologies, conventional high-frequency switching converters typically use a single inductor as the output filter inductor. However, the large size of a single inductor increases the overall size of the converter. Furthermore, a high-current acquisition device is required to sample the large current generated by the single inductor, further increasing the size of the converter and thus affecting its integration. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the integration density of high-frequency switching converters.

[0005] To address the above problems, this invention provides a current sampling system for a high-frequency switching converter.

[0006] In a first aspect, the present invention provides a current sampling system for a high-frequency switching converter, comprising a switching unit, a dual-winding coupled inductor, a current sensor, a voltage divider unit, and a control unit. The input terminal of the switching unit is connected to a power supply. The first output terminal of the switching unit is connected to the first terminal of the dual-winding coupled inductor. The second output terminal of the switching unit is connected to the second terminal of the dual-winding coupled inductor. The first terminal of the voltage divider unit is connected to the first and second terminals of the dual-winding coupled inductor, respectively. The second terminal of the voltage divider unit is connected to the negative terminal of the power supply. The third terminal of the voltage divider power supply is connected to the first input terminal of the control unit. The second input terminal of the control unit is connected to the first or second terminal of the dual-winding coupled inductor via the current sensor. The output terminal of the control unit is connected to the control terminal of the switching unit.

[0007] Optionally, the switching unit includes a first half-bridge switch and a second half-bridge switch. The input terminals of the first half-bridge switch and the second half-bridge switch are connected in parallel and then connected to the power supply. The output terminal of the first half-bridge switch is connected to the first corresponding terminal, and the output terminal of the second half-bridge switch is connected to the second corresponding terminal. The output terminal of the control unit is connected to the control terminals of the second half-bridge switch and the first half-bridge switch, respectively.

[0008] Optionally, the first half-bridge switch includes a first power transistor and a second power transistor. The drain of the first power transistor is connected to the positive terminal of the power supply. The source of the first power transistor is connected to the drain of the second power transistor to form the midpoint of the first half-bridge. The midpoint of the first half-bridge is connected to a first corresponding terminal. The source of the second power transistor is connected to the negative terminal of the power supply. The second half-bridge switch includes a third power transistor and a fourth power transistor. The drain of the third power transistor is connected to the positive terminal of the power supply. The source of the third power transistor is connected to the drain of the fourth power transistor to form the midpoint of the second half-bridge. The midpoint of the second half-bridge is connected to a second corresponding terminal. The source of the fourth power transistor is connected to the negative terminal of the power supply. The first output terminal of the control unit is connected to the control terminal of the first power transistor. The second output terminal of the control unit is connected to the control terminal of the second power transistor. The third output terminal of the control unit is connected to the control terminal of the third power transistor. The fourth output terminal of the control unit is connected to the control terminal of the fourth power transistor.

[0009] Optionally, the voltage divider unit includes a first resistor and a second resistor. One end of the first resistor is connected to the first and second opposite terminals of the dual-winding coupled inductor, respectively. The other end of the first resistor is connected to the first input terminal of the control unit. One end of the second resistor is connected to the other end of the first resistor, and the other end of the second resistor is connected to the negative terminal of the power supply.

[0010] Optionally, the control unit includes a voltage regulation module, a current regulation module, a comparator, and an output module; The voltage regulation module is used to: obtain a current control signal through proportional-integral regulation based on the voltage value at the third terminal of the voltage divider unit and the preset desired voltage; The current regulation module is used to: obtain a modulation signal by proportional adjustment based on the current control signal and the sampling signal collected by the current sensor; The comparator is used to: compare the modulation signal obtained from the non-inverting input with the preset triangular wave signal from the inverting input, and then output a control signal; The output unit is used to output a drive signal to the control terminal of the switching unit according to the control signal.

[0011] Optionally, the output unit includes a first driving unit, a second driving unit, and an inverter. The input terminal of the first driving unit is connected to the output terminal of the comparator, and the output terminal of the first driving unit is connected to the control terminal of the first power transistor and the control terminal of the third power transistor, respectively. The input terminal of the second driving unit is connected to the output terminal of the comparator through the inverter, and the output terminal of the second driving unit is connected to the control terminal of the second power transistor and the control terminal of the fourth power transistor, respectively.

[0012] Optionally, the first driving unit is used to: generate a driving signal for the first power transistor and a driving signal for the third power transistor according to the control signal; The second driving unit is used to generate driving signals for the second power transistor and the fourth power transistor based on the control signal processed by the inverter.

[0013] Optionally, a current control signal is obtained through proportional-integral regulation based on the voltage value at the third terminal of the voltage divider unit and a preset desired voltage, including: The voltage deviation is obtained based on the difference between the voltage value and the preset expected voltage value; The current control signal is obtained by proportional-integral adjustment based on the voltage deviation.

[0014] Optionally, a modulation signal is obtained by proportional adjustment based on the current control signal and the sampling signal acquired by the current sensor, including: The current deviation is obtained based on the difference between the current control signal and the sampled signal; The modulation signal is obtained by proportional adjustment based on the current deviation.

[0015] Optionally, the system also includes a voltage regulator capacitor, one end of which is connected to the first terminal of the voltage divider circuit, and the other end of which is connected to the second terminal of the voltage divider circuit.

[0016] The beneficial effects of the current sampling system of the high-frequency switching converter of the present invention are as follows: By using a dual-winding coupled inductor instead of a traditional single inductor, the dual-winding coupled inductor integrates the two windings into the same magnetic core through magnetic integration technology, significantly reducing the size of the inductor module and avoiding the problem of a single inductor occupying a large amount of space; at the same time, the first end of the voltage divider unit can be connected to the two opposite ends of the dual-winding coupled inductor simultaneously, sharing the same voltage divider unit, eliminating the need to design independent voltage divider structures for the two windings, reducing the number of voltage divider components and redundant wiring; and relying on the characteristic that the currents of the two opposite ends of the dual-winding coupled inductor are equal, only one current sensor is needed to sample the current of any one of the opposite ends to accurately reflect the output current of the entire dual-winding coupled inductor, eliminating the need for an additional current sensor. Through the simplified connection path of the switching unit, dual-winding coupled inductor, voltage divider unit, current sensor and control unit, there is no need for complex transition components between functional modules, the overall layout is more compact, effectively reducing the overall system volume, increasing the functional integration density per unit space, and thus significantly improving the integration of the high-frequency switching converter. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the current sampling system of a high-frequency switching converter according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the control unit in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a single-inductor converter in an embodiment of the present invention; Figure 4 This is a simulated waveform diagram of the high-frequency switching converter in an embodiment of the present invention; Figure 5 This is a schematic diagram of the magnetic core of the dual-winding coupled inductor in an embodiment of the present invention; Figure 6 This is a schematic diagram of the winding structure of the dual-winding coupled inductor in an embodiment of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0020] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0021] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0022] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0023] In related technologies, such as Figure 3 As shown, high-frequency switching converters commonly use a single inductor Lp as the output filter inductor. However, this single inductor Lp must simultaneously meet the requirements of ripple suppression and full current carrying. To reduce output current ripple and ensure stable power supply, a sufficiently large inductance value is required, necessitating an increase in core size. To carry the entire output current of the converter and prevent winding overheating or core saturation, thicker winding wires and a further increase in core cross-sectional area are necessary. These dual requirements result in a large single inductor size, thus increasing the overall converter size. Simultaneously, the large current generated by the single inductor requires sampling using large current transformers Cp and other equipment. These sampling devices themselves occupy significant space, further compressing the internal layout space of the converter. The combined effect makes it difficult to compactly arrange internal components, reducing the integration capability of functional modules within a unit space and ultimately significantly weakening the integration density of the high-frequency switching converter.

[0024] To address the problems existing in the aforementioned related technologies, embodiments of the present invention provide a current sampling system for a high-frequency switching converter.

[0025] like Figure 1 As shown in the figure, an embodiment of the present invention provides a current sampling system for a high-frequency switching converter, including a switching unit, a dual-winding coupled inductor, a current sensor, a voltage divider unit, and a control unit. The input terminal of the switching unit is connected to a power supply. The first output terminal of the switching unit is connected to the first terminal of the dual-winding coupled inductor. The second output terminal of the switching unit is connected to the second terminal of the dual-winding coupled inductor. The first terminal of the voltage divider unit is connected to the first and second terminals of the dual-winding coupled inductor, respectively. The second terminal of the voltage divider unit is connected to the negative terminal of the power supply. The third terminal of the voltage divider power supply is connected to the first input terminal of the control unit. The second input terminal of the control unit is connected to the first or second terminal of the dual-winding coupled inductor through the current sensor. The output terminal of the control unit is connected to the control terminal of the switching unit.

[0026] Specifically, the input terminal of the switching unit is connected to the power supply U. IN Connect to obtain electrical energy; this power supply can be a DC power supply. The two output terminals of the switching unit are respectively connected to the first terminal L of the dual-winding coupled inductor Lo. O1 Second terminal L O2 The connection utilizes a dual-winding coupled inductor Lo instead of a traditional single inductor, optimizing both size and heat dissipation while achieving filtering and energy transfer through the coupling effect between the windings. The first terminal of the voltage divider unit is simultaneously connected to the first opposite-named terminal L of the dual-winding coupled inductor Lo. O3 Second heteronym L O4 The second terminal of the voltage divider unit is directly connected to the power supply U. INThe negative terminal of the circuit is connected to form a loop. The third terminal of the voltage divider unit transmits the voltage signal collected from the opposite-named terminal of the inductor to the first input terminal IN1 of the control unit ICMCU, providing voltage feedback for the control unit ICMCU. The current sensor CS, as a key component for current sampling, is connected at one end to the second input terminal IN2 of the control unit, and at the other end to any opposite-named terminal of the dual-winding coupled inductor Lo. That is, the current sensor CS can be connected to the first opposite-named terminal to collect the voltage signal from the first opposite-named terminal L. O3 The output current signal, or connected to the second non-nominated terminal, is used to acquire the data from the second non-nominated terminal L. O4 Since the current outputs of the two opposite terminals of the dual-winding coupled inductor Lo are equal, the current at either opposite terminal can be sampled using a single current sensor CS. This sampled current signal reflects the true trend and state of the output current of the dual-winding coupled inductor Lo. By acquiring the current signal output by the dual-winding coupled inductor Lo in real time and feeding it back to the control unit, the control unit performs comprehensive analysis based on the received voltage and current signals. It then sends a control signal to the control terminal of the switching unit through its output terminal to dynamically adjust the on / off state of the switching unit, thereby achieving precise control of the converter's output voltage and current and ensuring stable operation of the entire system. The output terminals (V1 and V2) of the high-frequency switching converter are connected in parallel with the voltage divider unit at the same node, i.e., the first output terminal V1 of the high-frequency switching converter and the first opposite terminal L... O3 Second synonym L O4 The first terminal of the voltage divider unit (one end of the first resistor R1) is connected together with the second output terminal V2 of the high-frequency switching converter, which is connected to the second terminal of the voltage divider unit (the other end of the second resistor R2) and the power supply U. IN The negative terminals of V1 and V2 are connected together, and the load R0 is connected between V1 and V2. This parallel structure allows the voltage divider circuit to sample the output voltage (the voltage across the load R0) and transmit the sampled signal to the first input terminal of the control unit, thereby realizing the monitoring and control of the output voltage.

[0027] It should be noted that if the coupling coefficient of the dual-winding coupled inductor Lo is too large, it will cause a short circuit in the coupled inductor winding, inducing circulating current; if the coupling coefficient is too small, the coupled inductance Lo will become smaller, resulting in large current ripple. For example... Figure 4 The diagram shows the simulation results, where the horizontal axis represents time T (msecs) and the vertical axis represents current I (kA). A coupling coefficient k=0.9 results in minimal ripple, but significant current imbalance between the two windings; k=0.3 results in minimal current difference between the two windings, but with large ripple; coupling coefficients between 0.5 and 0.6 provide acceptable current sharing and ripple amplitude. Figure 5 and Figure 6The coupled inductor core is designed with a rectangular structure and symmetrical side pillars. It consists of four parts: two identical side pillars and two identical end pillars. Windings 1 and 2, with the same number of turns and the same wire diameter, are symmetrically distributed on the two side pillars. Measurements using wound samples show that the inductance deviation between the two windings can be controlled to ≤1.5%, and the coupling coefficient meets the requirement of 0.5 to 0.6. The parameters of the dual-winding coupled inductor Lo are as follows: The positive inductance satisfies: L a =L1+L2+2×M; The reverse inductance satisfies: L b =L1+L2-2×M; The coupling coefficients satisfy: ; Among them, L a For positive connection inductance (series inductance with opposite terminals), L b For reverse connection inductance (inductances connected in series at the same terminals), L1 is the self-inductance of winding 1, L2 is the self-inductance of winding 2, M is the mutual inductance of the coupled inductance, and K is the coupling coefficient.

[0028] In this embodiment, a dual-winding coupled inductor Lo is used instead of a traditional single inductor. The dual-winding coupled inductor integrates two windings onto a single magnetic core using magnetic integration technology, significantly reducing the size of the inductor module and avoiding the space-consuming problem of a single inductor. Simultaneously, the first end of the voltage divider unit can connect to both opposite terminals of the dual-winding coupled inductor Lo, eliminating the need for separate voltage divider structures for each winding and reducing the number of voltage divider components and redundant wiring. Furthermore, leveraging the characteristic that the currents at the two opposite terminals of the dual-winding coupled inductor Lo are equal, only one current sensor CS is needed to sample the current at either opposite terminal to accurately reflect the output current of the entire dual-winding coupled inductor Lo, eliminating the need for an additional current sensor. Through a simplified connection path between the switching unit, the dual-winding coupled inductor Lo, the voltage divider unit, the current sensor CS, and the control unit ICMCU, no complex adapters are required between functional modules, resulting in a more compact overall layout, effectively reducing the overall system size, increasing the functional integration density per unit space, and thus significantly improving the integration level of the high-frequency switching converter.

[0029] Optionally, such as Figure 1 As shown, the switching unit includes a first half-bridge switch and a second half-bridge switch. The input terminals of the first half-bridge switch and the second half-bridge switch are connected in parallel and then connected to the power supply. The output terminal of the first half-bridge switch is connected to the first corresponding terminal, and the output terminal of the second half-bridge switch is connected to the second corresponding terminal. The output terminal of the control unit is connected to the control terminals of the second half-bridge switch and the first half-bridge switch, respectively.

[0030] In this optional embodiment, the switching unit consists of a first half-bridge switch and a second half-bridge switch. Their input terminals are connected in parallel and then connected to a power supply to achieve parallel energy acquisition. The output terminal of the first half-bridge switch is connected to the first terminal L of the dual-winding coupled inductor Lo. O1 The output terminal of the second half-bridge switch is connected to the second terminal L of the dual-winding coupled inductor Lo. O2 The two windings of the dual-winding coupled inductor Lo are connected to drive each other. The output of the control unit ICMCU is connected to the control terminals of the first half-bridge switch and the second half-bridge switch respectively. The on / off state of the two half-bridge switches can be adjusted independently through the output control signal, thereby precisely controlling the current on / off and energy transfer of the dual-winding coupled inductor Lo, providing the core switching drive and control logic for the power conversion process of the high-frequency switching converter.

[0031] Optionally, such as Figure 1 As shown, the first half-bridge switch includes a first power transistor and a second power transistor. The drain of the first power transistor is connected to the positive terminal of the power supply, and the source of the first power transistor is connected to the drain of the second power transistor to form the midpoint of the first half-bridge. The midpoint of the first half-bridge is connected to the first corresponding terminal. The source of the second power transistor is connected to the negative terminal of the power supply. The second half-bridge switch includes a third power transistor and a fourth power transistor. The drain of the third power transistor is connected to the positive terminal of the power supply, and the source of the third power transistor is connected to the drain of the fourth power transistor to form the midpoint of the second half-bridge. The midpoint of the second half-bridge is connected to the second corresponding terminal. The source of the fourth power transistor is connected to the negative terminal of the power supply. The first output terminal of the control unit is connected to the control terminal of the first power transistor, the second output terminal of the control unit is connected to the control terminal of the second power transistor, the third output terminal of the control unit is connected to the control terminal of the third power transistor, and the fourth output terminal of the control unit is connected to the control terminal of the fourth power transistor.

[0032] In this optional embodiment, the first half-bridge switch includes a first power transistor Q1 and a second power transistor Q2, with the drain of the first power transistor Q1 directly connected to the power supply U. IN The positive terminal is connected, and the source terminal is connected to the first terminal L of the dual-winding coupled inductor Lo. O1 Connected, it acts as the "upper transistor" of this half-bridge, responsible for receiving power from the U... IN The positive terminal of the first transistor supplies current to the first winding; the drain of the second power transistor Q2 is connected to the first terminal L. O1 Connection, source connected to power supply U IN The negative terminal of the transistor acts as the "lower transistor," controlling the return current from the first winding to the negative terminal of the power supply. Correspondingly, the second half-bridge switch consists of a third power transistor Q3 and a fourth power transistor Q4. The third power transistor Q3 is also connected to the power supply U via its drain.IN The positive and source terminals are connected to the second terminal L of the dual-winding coupled inductor Lo. O2 This forms the forward current path for the second winding; the fourth power transistor Q4 is connected to the second terminal L via its drain. O2 The source terminal is connected to the negative terminal of the power supply, forming the reverse return path of the second winding. To achieve independent and precise control of the on / off states of the four power transistors, the control unit ICMCU is connected one-to-one with the control terminal of each transistor through four output terminals. Specifically, the first output terminal OUT1 is connected to the control terminal of the first power transistor Q1, the second output terminal OUT2 is connected to the control terminal of the second power transistor Q2, the third output terminal OUT3 is connected to the control terminal of the third power transistor Q3, and the fourth output terminal OUT4 is connected to the control terminal of the fourth power transistor Q4. This allows for flexible driving of different transistors to turn on or off according to the converter's operating requirements, thereby controlling the current on / off timing and energy transfer direction of the two windings of the dual-winding coupled inductor Lo, providing stable hardware support and control foundation for the core power conversion stage of the high-frequency switching converter.

[0033] Optionally, such as Figure 1 As shown, the voltage divider unit includes a first resistor and a second resistor. One end of the first resistor is connected to the first and second opposite terminals of the dual-winding coupled inductor, respectively. The other end of the first resistor is connected to the first input terminal of the control unit. One end of the second resistor is connected to the other end of the first resistor, and the other end of the second resistor is connected to the negative terminal of the power supply.

[0034] In this optional embodiment, one end of the first resistor R1 serves as a common connection terminal, and is simultaneously connected to the first opposite-name terminal L of the dual-winding coupled inductor Lo. O1 Second heteronym L O2 This design, relying on the characteristics of equal current and correlated voltage states at opposite ends of the dual windings, eliminates the need for separate voltage divider branches for the two opposite ends, simplifying the circuit structure. The other end of the first resistor R1 is connected to IN1, the first input terminal of the control unit IC MCU (used to transmit the sampled voltage signal). One end of the second resistor R2 is connected to the other end of the first resistor R1, and the other end of the second resistor R2 is directly connected to the power supply U. IN The negative terminal is connected, forming a complete series voltage divider circuit between the first resistor R1 and the second resistor R2. When the dual-winding coupled inductor Lo is working, the voltage signal at its opposite terminal is divided by the first resistor R1 and the second resistor R2, and the voltage signal that matches the sampling range of the control unit ICMUC is sent to the first input terminal IN1 of the control unit ICMUC. This provides a reliable voltage feedback basis for the control unit ICMUC to monitor the output voltage and adjust the on / off timing of the switching unit. At the same time, this simplified series voltage divider design also reduces the number of components and wiring complexity, which meets the requirements of improving the integration of the converter.

[0035] Optionally, such as Figure 2 As shown, the control unit includes a voltage regulation module, a current regulation module, a comparator, and an output module; The voltage regulation module is used to: obtain a current control signal through proportional-integral regulation based on the voltage value at the third terminal of the voltage divider unit and the preset desired voltage; The current regulation module is used to: obtain a modulation signal by proportional adjustment based on the current control signal and the sampling signal collected by the current sensor; The comparator is used to: compare the modulation signal obtained from the non-inverting input with the preset triangular wave signal from the inverting input, and then output a control signal; The output unit is used to output a drive signal to the control terminal of the switching unit according to the control signal.

[0036] In this optional embodiment, the input to voltage regulation module 1 is the actual voltage signal Uc transmitted from the third terminal of the voltage divider unit (i.e., the voltage after voltage division at the opposite terminals of the dual-winding coupled inductor Lo, reflecting the output voltage state of the converter), and also a preset desired voltage Uref (target output voltage value). The deviation between the actual voltage signal Uc and the desired voltage Uref is processed using a proportional-integral (PI) regulation algorithm to ultimately generate a current control signal for constraining the current, providing a reference for subsequent current regulation. Current regulation module 2 receives the current control signal from voltage regulation module 1 and simultaneously receives the actual current sampling signal ICS collected by current sensor CS (reflecting the operating current at any opposite terminal of the dual-winding coupled inductor Lo). The deviation between the current control signal and the actual current sampling signal ICS is calculated using a proportional regulation algorithm K, and an analog signal (i.e., a modulation signal) that can be used for modulation is output. Comparator D, a key component of pulse width modulation (PWM), receives the modulation signal from the current regulation module 1 at its non-inverting input and a triangular wave signal SJ with a preset frequency and amplitude at its inverting input. By comparing the modulation signal with the triangular wave signal SJ in real time, it outputs a control signal that alternates between high and low levels, achieving preliminary control of the switching timing. Output unit 3 amplifies or performs level matching processing on the control signal output from comparator D, converting it into drive signals (PWM1, PWM2, PWM3, and PWM4) that can be recognized by the switching units (each power transistor), and accurately sends them to the control terminals of the switching units. Ultimately, this achieves dynamic regulation of the switching unit's on / off state, ensuring that the converter's output voltage and current remain stable within the target range.

[0037] Optionally, such as Figure 1 and Figure 2As shown, the output unit includes a first driving unit, a second driving unit, and an inverter. The input terminal of the first driving unit is connected to the output terminal of the comparator, and the output terminal of the first driving unit is connected to the control terminal of the first power transistor and the control terminal of the third power transistor, respectively. The input terminal of the second driving unit is connected to the output terminal of the comparator through the inverter, and the output terminal of the second driving unit is connected to the control terminal of the second power transistor and the control terminal of the fourth power transistor, respectively.

[0038] Optionally, such as Figure 1 and Figure 2 As shown, the first driving unit is used to: generate driving signals for the first power transistor and driving signals for the third power transistor according to the control signal; The second driving unit is used to generate driving signals for the second power transistor and the fourth power transistor based on the control signal processed by the inverter.

[0039] In this optional embodiment, the first driving unit DU1 and the second driving unit DU2 included in the output unit 3 are mainly responsible for amplifying or conditioning the control signal (PWM signal) output by the comparator D, enabling it to drive the power transistors to turn on / off. The input terminal of the first driving unit DU1 is directly connected to the output terminal of the comparator D, receiving the original PWM control signal. Its output terminal is simultaneously connected to the control terminals of the first power transistor Q1 and the third power transistor Q3, ensuring that Q1 and Q3 receive identical driving signals PWM1 and PWM3, thus achieving synchronous on / off. The input terminal of the second driving unit DU2 is not directly connected to the output terminal of the comparator D, but rather connected through an inverter FX. The inverter FX flips the phase of the original PWM signal output by the comparator (i.e., inverts the original signal when it is high). (The following is a low level, and vice versa), and then the inverted PWM signal is sent to the second drive unit DU2. The output of the second drive unit DU2 is simultaneously connected to the control terminals of the second power transistor Q2 and the fourth power transistor Q4, so that Q2 and Q4 receive synchronous drive signals that are 180 degrees out of phase with Q1 and Q3. This satisfies the drive rule that "Q1 and Q3 are in phase, Q2 and Q4 are in phase, and the two sets of phases are opposite", and also avoids the short circuit caused by the simultaneous conduction of the upper and lower transistors in the same half-bridge (such as Q1 and Q2, Q3 and Q4). This provides a reliable drive signal guarantee for the safe and stable operation of the high-frequency switching converter.

[0040] Optionally, such as Figure 2 As shown, the current control signal is obtained through proportional-integral regulation based on the voltage value at the third terminal of the voltage divider unit and the preset desired voltage, including: The voltage deviation is obtained based on the difference between the voltage value and the preset expected voltage value; The current control signal is obtained by proportional-integral adjustment based on the voltage deviation.

[0041] In this optional embodiment, the voltage value from the third terminal of the voltage divider unit is the feedback actual voltage signal Uc obtained by dividing the voltage at the opposite terminals of the dual-winding coupled inductor Lo through the first resistor R1 and the second resistor R2. This signal accurately reflects the current actual output voltage (voltage across the load R0) of the high-frequency switching converter. The preset expected voltage Uref is a target output voltage pre-set according to the requirements of the converter load R0 or system design specifications, representing the ideal voltage level that the converter should achieve. Subsequently, by calculating the difference between the actual voltage signal Uc fed back by the voltage divider unit and the preset expected voltage Uref, i.e., Uref-Uc, the voltage deviation between the two is obtained. This deviation directly reflects the gap between the current output voltage and the target voltage and is the core basis for subsequent adjustment. Next, voltage regulation module 1 will execute a proportional-integral (PI) regulation algorithm on the voltage deviation: the "proportional regulation" part will output a regulation amount according to a fixed proportion based on the instantaneous magnitude of the voltage deviation, quickly responding to the deviation to initially reduce the gap between the actual voltage and the target voltage; the "integral regulation" part will accumulate the voltage deviation over time, gradually eliminating the static error that may remain due to proportional regulation (i.e., the small deviation in which the actual voltage cannot completely reach the target voltage during long-term operation). Through the synergistic effect of proportional and integral, a stable and accurate current control signal is finally generated. This signal will serve as the control reference for the subsequent current regulation module 2, laying the foundation for further regulating the converter output current and ultimately achieving output voltage stability.

[0042] Optionally, such as Figure 2 As shown, based on the current control signal and the sampling signal collected by the current sensor, a modulation signal is obtained through proportional adjustment, including: The current deviation is obtained based on the difference between the current control signal and the sampled signal; The modulation signal is obtained by proportional adjustment based on the current deviation.

[0043] In this optional embodiment, the current control signal is generated by the preceding voltage regulation module 1. It is a current reference value determined based on the output voltage deviation after proportional-integral (PI) regulation, directly reflecting the ideal current level required to stabilize the output voltage at the preset desired voltage. The sampling signal ICS is acquired by the current sensor CS, corresponding to the actual current data of the dual-winding coupled inductor Lo during operation, truly reflecting the current actual current state of the converter. Subsequently, by performing a difference calculation between the current control signal (ideal current reference) and the sampling signal ICS (actual current data), the current deviation between the two is obtained. This deviation directly reflects the difference between the current actual current and the ideal reference current, and is the core basis for subsequent current regulation. If the deviation is positive, it means that the actual current is lower than the reference value, and the current needs to be increased; if the deviation is negative, the current needs to be decreased. Next, the current regulation module 2 executes the proportional regulation K algorithm on the current deviation: the algorithm converts the current deviation into an adjustment amount according to a preset proportional coefficient. Since proportional regulation has the characteristic of instant response, it can quickly output the corresponding adjustment signal according to the change of current deviation, and finally generate an analog signal (i.e., modulation signal) for subsequent PWM modulation. This modulation signal will be used as the input signal of the non-inverting input terminal of the comparator D, providing a precise current loop adjustment basis for subsequent comparison with the triangular wave signal SJ to generate the switching control signal, ensuring that the converter output current stably tracks the current control signal, thereby helping to maintain the stability of the output voltage.

[0044] Optionally, such as Figure 1 As shown, the system also includes a voltage regulator capacitor, one end of which is connected to the first terminal of the voltage divider circuit, and the other end of which is connected to the second terminal of the voltage divider circuit.

[0045] In this optional embodiment, one end of the voltage regulator capacitor C0 is connected to the first end of the voltage divider circuit (i.e., the first resistor in the voltage divider unit is connected to the first opposite-named terminal L of the dual-winding coupled inductor Lo). O3 Second synonym L O4 One end is connected to the common terminal of the voltage divider circuit, and the other end is connected to the second terminal of the voltage divider circuit (i.e., the second resistor R2 in the voltage divider unit is connected to the power supply U). INThe voltage divider circuit connects the negative terminal of the capacitor C0 to the output terminals (V1, V2) of the voltage divider circuit, which consists of the first resistor R1 and the second resistor R2. Essentially, it connects the voltage regulator C0 in parallel with the negative terminal of the voltage divider circuit. The core function of the voltage divider circuit is to acquire the voltage signal Uc from either of the opposite terminals of the dual-winding coupled inductor Lo and transmit it to the control unit ICMCU. However, during high-frequency switching converter operation, the voltage of the dual-winding coupled inductor Lo is prone to high-frequency ripple due to switching action. This ripple causes fluctuations in the voltage feedback signal output by the voltage divider circuit, affecting the accuracy of the control unit's judgment of the output voltage. The voltage regulator C0, connected in parallel across the voltage divider circuit, can absorb voltage ripple using its charging and discharging characteristics, smoothing the voltage signal output by the voltage divider circuit and reducing the impact of high-frequency interference on the feedback signal. This makes the voltage feedback signal Uc transmitted to the first input terminal of the control unit ICMCU more stable and accurate, thereby helping the control unit ICMCU generate precise control commands based on reliable voltage information, ensuring the stability of the high-frequency switching converter's output voltage. It also further optimizes the performance of the voltage divider unit, working synergistically with the voltage divider circuit to improve the overall system's anti-interference capability.

[0046] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A current sampling system for a high frequency switching converter, characterized by, The application relates to a switching unit, a double-winding coupled inductor, a current sensor, a voltage dividing unit and a control unit, an input end of the switching unit is used for being connected with a power supply, a first output end of the switching unit is connected with a first same-named end of the double-winding coupled inductor, a second output end of the switching unit is connected with a second same-named end of the double-winding coupled inductor, a first end of the voltage dividing unit is connected with a first different-named end and a second different-named end of the double-winding coupled inductor respectively, a second end of the voltage dividing unit is connected with a negative pole of the power supply, a third end of the voltage dividing unit is connected with a first input end of the control unit, a second input end of the control unit is connected with the first different-named end or the second different-named end of the double-winding coupled inductor through the current sensor, and an output end of the control unit is connected with a control end of the switching unit.

2. The current sampling system of a high-frequency switching converter according to claim 1, characterized in that, The switching unit comprises a first half-bridge switch and a second half-bridge switch, the input ends of the first half-bridge switch and the second half-bridge switch are connected in parallel and then connected with the power supply, the output end of the first half-bridge switch is connected with the first same-named end, the output end of the second half-bridge switch is connected with the second same-named end, and the output end of the control unit is connected with the control ends of the second half-bridge switch and the first half-bridge switch respectively.

3. The current sampling system of a high-frequency switched converter according to claim 2, characterized in that, The first half-bridge switch comprises a first power transistor and a second power transistor, the drain of the first power transistor is connected with the positive pole of the power supply, the source of the first power transistor is connected with the drain of the second power transistor to form a first half-bridge midpoint, the first half-bridge midpoint is connected with the first same-named end, and the source of the second power transistor is connected with the negative pole of the power supply, the second half-bridge switch comprises a third power transistor and a fourth power transistor, the drain of the third power transistor is connected with the positive pole of the power supply, the source of the third power transistor is connected with the drain of the fourth power transistor to form a second half-bridge midpoint, the second half-bridge midpoint is connected with the second same-named end, and the source of the fourth power transistor is connected with the negative pole of the power supply, the first output end of the control unit is connected with the control end of the first power transistor, the second output end of the control unit is connected with the control end of the second power transistor, the third output end of the control unit is connected with the control end of the third power transistor, and the fourth output end of the control unit is connected with the control end of the fourth power transistor.

4. The current sampling system of a high-frequency switching converter according to claim 3, characterized in that, The voltage dividing unit comprises a first resistor and a second resistor, one end of the first resistor is connected with the first different-named end and the second different-named end of the double-winding coupled inductor respectively, the other end of the first resistor is connected with the first input end of the control unit, one end of the second resistor is connected with the other end of the first resistor, and the other end of the second resistor is connected with the negative pole of the power supply.

5. The current sampling system of a high-frequency switching converter according to claim 3, wherein, The control unit comprises a voltage regulating module, a current regulating module, a comparator and an output module. The voltage regulating module is configured to obtain a current control signal by proportional-integral regulation according to a voltage value of the third end of the voltage dividing unit and a preset expected voltage; The current regulating module is configured to obtain a modulation signal by proportional regulation according to the current control signal and a sampling signal collected by the current sensor; The comparator is configured to output a control signal after comparing the modulation signal obtained by the in-phase input end with a preset triangular wave signal of the reverse input end; The output unit is configured to output a driving signal to the control end of the switching unit according to the control signal.

6. The current sampling system of a high-frequency switching converter according to claim 5, characterized in that, The output unit comprises a first driving unit, a second driving unit and an inverter, the input end of the first driving unit is connected with the output end of the comparator, the output end of the first driving unit is connected with the control end of the first power transistor and the control end of the third power transistor respectively, the input end of the second driving unit is connected with the output end of the comparator through the inverter, and the output end of the second driving unit is connected with the control end of the second power transistor and the control end of the fourth power transistor respectively.

7. The current sampling system of a high-frequency switched converter according to claim 6, characterized in that, The first driving unit is configured to generate the driving signal of the first power transistor and the driving signal of the third power transistor according to the control signal; The second driving unit is configured to generate the driving signal of the second power transistor and the driving signal of the fourth power transistor according to the control signal processed by the inverter.

8. The current sampling system of a high-frequency switching converter according to claim 5, wherein, The current control signal obtained by proportional-integral regulation according to the voltage value of the third end of the voltage dividing unit and a preset expected voltage comprises: a voltage deviation is obtained according to the difference between the voltage value and the preset expected voltage value; the current control signal is obtained by proportional-integral regulation according to the voltage deviation.

9. The current sampling system of a high-frequency switching converter according to claim 5, wherein, The modulation signal obtained by proportional regulation according to the current control signal and the sampling signal collected by the current sensor comprises: a current deviation is obtained according to the difference between the current control signal and the sampling signal; the modulation signal is obtained by proportional regulation according to the current deviation.

10. The current sampling system of a high-frequency switched converter according to claim 1, characterized in that, Further comprising a voltage stabilizing capacitor, one end of the voltage stabilizing capacitor is connected with the first end of the voltage dividing circuit, and the other end of the voltage stabilizing capacitor is connected with the second end of the voltage dividing circuit.

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