High-efficiency isolation circuit with low output ripples

Abstract

The invention belongs to the technical field of circuits, and discloses an efficient isolation circuit with low output ripples, which comprises a capacitor C3, one end of the capacitor C3 is connected with a pin 1 of an inductor L1, a pin 2 of the inductor L1 is connected with a pin 1 of a switching tube Q1 and one end of a capacitor C1, the other end of the capacitor C1 is connected with a pin 1 of a transformer T1, the other end of the C3 is connected with a pin 2 of the Q1 and a pin 2 of the T1, and the other end of the capacitor C1 is connected with a pin 2 of the transformer T1. The pin 3 of the T1 is connected with the pin 2 of the Q2 and one end of the C4, the pin 4 of the T1 is connected with one end of the C2, the other end of the C2 is connected with the pin 1 of the Q2 and the pin 1 of the L2, the pin 2 of the L2 is connected with the other end of the C4, the L1 and the L2 are coupled, the pin 1 of the L1 and the pin 2 of the L2 are dotted terminals, and the pin 1 and the pin 4 of the T1 are dotted terminals. The beneficial effects of the invention are that efficient conversion and low output ripple of electric energy are realized through an innovative circuit structure and an optimized working principle.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to a high-efficiency isolation circuit with low output ripple. Background Art

[0002] The converter converts the information sent by the source for a certain purpose, such as the mutual conversion between AC and DC, DC and DC, to meet different application requirements. In order to simplify the design, reduce the conversion links, reduce losses, and improve system efficiency, unidirectional converters are gradually transformed into bidirectional converters. Traditional DCDC circuits have problems such as low conversion efficiency and large output ripple during the power conversion process. In order to improve these problems, although the bidirectional converters in the prior art have made certain progress, they still have shortcomings such as complex design and many conversion links. A new type of isolated DCDC circuit is urgently needed to simplify the design, reduce the conversion links, improve the conversion efficiency, and reduce the output ripple.

[0003] Therefore, it is necessary to provide a high-efficiency isolation circuit with low output ripple to achieve high-efficiency conversion of electric energy and low output ripple. Summary of the invention

[0004] The present invention discloses a high-efficiency isolation circuit with low output ripple, and relates to the field of power management technology. Specifically, it is an isolation DCDC (direct current-to-direct current converter) circuit with low output ripple and high-efficiency conversion. The circuit is suitable for electric vehicles, renewable energy power generation systems, data centers and other occasions requiring high-efficiency and stable power conversion and transmission, and can effectively solve the technical problems involved in the background technology.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A high-efficiency isolation circuit with low output ripple comprises a capacitor C3, one end of the capacitor C3 is connected to pin 1 of an inductor L1, pin 2 of the inductor L1 is connected to pin 1 of a switch tube Q1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to pin 1 of a transformer T1, the other end of the capacitor C3 is connected to pin 2 of the switch tube Q1 and pin 2 of the transformer T1, pin 3 of the transformer T1 is connected to pin 2 of the switch tube Q2 and one end of a capacitor C4, pin 4 of the transformer T1 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to pin 1 of the switch tube Q2 and pin 1 of an inductor L2, pin 2 of the inductor L2 is connected to the other end of the capacitor C4, the inductor L1 is coupled to the inductor L2, pin 1 of the inductor L1 and pin 2 of the inductor L2 are same-name terminals, and pin 1 and pin 4 of the transformer T1 are same-name terminals. The purpose of the present invention is to provide a high-efficiency isolated DCDC circuit with low output ripple, which realizes high-efficiency conversion of electric energy and low output ripple through an innovative circuit structure and an optimized working principle.

[0007] As a preferred improvement of the present invention: the capacitor C3 is connected to a power supply, and the capacitor C4 is connected to a load, or the capacitor C3 is connected to a load, and the capacitor C4 is connected to a power supply.

[0008] As a preferred improvement of the present invention: the switch tube Q1 and the switch tube Q2 are both MOS tubes, IGBTs or other semiconductor switch devices. When they are MOS tubes, pin 1 is the drain and pin 2 is the source.

[0009] As a preferred improvement of the present invention: the gates of the switch tube Q1 and the switch tube Q2 are both connected to a drive circuit controlled by an MCU.

[0010] As a preferred improvement of the present invention: Pin 1 and Pin 2 of the transformer T1 share a coil, and Pin 3 and Pin 4 of the transformer T1 share a coil.

[0011] As a preferred improvement of the present invention: the circuit is used for DCDC conversion.

[0012] The beneficial effects of the present invention are as follows:

[0013] Contrary to the traditional circuit, the transformer has the same-name end modified, which changes the phase relationship of the voltage and thus affects the working characteristics of the circuit. In addition, the inductance of the primary and secondary sides is made into a coupled inductor. This design can enhance the electromagnetic coupling between the inductors, which helps to achieve more efficient power transmission and conversion. It provides a high-efficiency isolated DCDC circuit with low output ripple. Through innovative circuit structure and optimized working principle, efficient conversion of electric energy and low output ripple are achieved, and the circuit structure is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0015] Figure 1 A schematic diagram of a conversion circuit;

[0016] Figure 2 A schematic diagram of a high-efficiency isolation circuit with low output ripple according to the present invention;

[0017] Figure 3 The circuit principle of the present invention is shown in FIG. Figure 1 ;

[0018] Figure 4The circuit principle of the present invention is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0021] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] See also Figure 1 As shown, Figure 1It is a converter circuit, C13 is used as the input filter capacitor, and C14 is used as the output filter capacitor. The steady-state working process is as follows: when Q11 is turned on and Q12 is turned off, the current of inductor L11 increases, capacitor 11 is connected in parallel with the primary side of transformer T, and the voltage of capacitor C11 is superimposed on the voltage of capacitor C12 through transformer T. After being filtered by L12 and C14, power is supplied to the load. When Q11 is turned off, the current of inductor L11 decreases. At this time, the inductor voltage commutates, and the primary voltage of transformer T increases from the negative maximum to the positive maximum. The body diode of Q12 is turned on due to forward bias. At this time, Q12 is turned on, L12 enters the freewheeling stage, the current decreases, the voltage reverses, and continues to charge C14. V C14 =-L12dL12 / dt. Vs transformer secondary voltage, when Vs+V C12 -V C14 When it drops to zero and becomes negative, the inductor current L12 starts to drop from the maximum. When the inductor current L12 is close to zero, Q11 is turned on, the inductor current L12 starts to rise, and the transformer turns ratio is equal to 1:n. When Q11 is turned off, the current of the inductor L11 drops, and the voltage across it changes direction. The voltage stress across the switch tube is V C13 -L11di L11 / dt, greater than the input voltage V C13 When Q12 is turned off, the voltage stress across it is Vc 14 +L12di L12 / dt, greater than the output voltage V C14 When the switch tubes Q11 and Q12 are turned off, the voltage stress is greater than the input voltage and the output voltage, and the isolated DC output or the output cannot be directly connected to the commonly used three-level inverter circuit DC / AC.

[0025] See also Figure 2 As shown, based on Figure 1In order to solve the problem in the invention, the present invention provides a high-efficiency isolation circuit with low output ripple, comprising a capacitor C3, one end of the capacitor C3 is connected to pin 1 of an inductor L1, pin 2 of the inductor L1 is connected to pin 1 of a switch tube Q1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to pin 1 of a transformer T1, the other end of the capacitor C3 is connected to pin 2 of the switch tube Q1 and pin 2 of the transformer T1, pin 3 of the transformer T1 is connected to pin 2 of the switch tube Q2 and one end of a capacitor C4, pin 4 of the transformer T1 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to pin 1 of the switch tube Q2 and pin 1 of the inductor L2, pin 2 of the inductor L2 is connected to the other end of the capacitor C4, the inductor L1 and the inductor L2 are coupled (can also be regarded as two coils of coupled inductance), pin 1 of the inductor L1 and pin 2 of the inductor L2 are the same-named ends, and pin 1 and pin 4 of the transformer T1 are the same-named ends. The capacitor C3 is connected to a power supply, and the capacitor C4 is connected to a load, or the capacitor C3 is connected to a load, and the capacitor C4 is connected to a power supply. The switch tube Q1 and the switch tube Q2 are both MOS tubes, wherein pin 1 is a drain, pin 2 is a source, and the gates of the switch tubes Q1 and Q2 are both connected to the MCU. Pins 1 and 2 of the transformer T1 share a coil, and pins 3 and 4 of the transformer T1 share a coil. The circuit is used for DCDC conversion, and through innovative circuit structure and optimized working principle, efficient conversion of electric energy and low output ripple are achieved.

[0026] Specifically, the circuit includes an input filter capacitor C3, an output filter capacitor C4, inductors L1 and L2, a transformer T1, switch tubes Q1 and Q2, and capacitors C1 and C2. Among them, the transformer's same-name segments are opposite to the traditional circuit, and L1 and L2 are coupled inductors. Changes to the transformer's same-name segments: Contrary to the traditional circuit, this change changes the phase relationship of the voltage, which in turn affects the circuit's operating characteristics. Application of coupled inductors: The inductors on the primary and secondary sides are made into coupled inductors. This design can enhance the electromagnetic coupling between the inductors, which helps to achieve more efficient power transmission and conversion.

[0027] Working principle: See Figure 3-Figure 4

[0028] When Q1 is turned on: inductor L1 is charged, and because L1 and L2 are coupled inductors, the power supply charges C4 through the coupled inductor to supply power to the load. At the same time, C1 discharges to charge C2. This process involves the storage and release of electrical energy, as well as voltage conversion.

[0029] When Q1 is turned off: the power supply charges C1 through L1 and supplies power to the secondary side through the transformer. At this time, C2 discharges through L2 and continues to supply power to the load. Since L1 and L2 are coupled inductors, L1 has a damping effect on L2, making the discharge process of L2 smoother and helping to reduce output ripple.

[0030] The present invention relates to the field of power management technology, and specifically to an isolated DCDC (direct current-to-direct current converter) circuit with low output ripple and high-efficiency conversion, which is suitable for electric vehicles, renewable energy power generation systems, data centers and other occasions that require efficient and stable power conversion and transmission. Compared with traditional DCDC circuits, the present invention has been innovated and optimized in structure, reducing the number of conversion links and components, thereby simplifying the design process. Through the application of coupled inductors and the optimization of circuit structure, the present invention realizes efficient conversion of electric energy and significantly improves conversion efficiency. The design of coupled inductors and the application of damping effect significantly reduce the output ripple and improve the stability and reliability of the circuit.

[0031] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A high efficiency isolation circuit with low output ripple, characterized in that: It includes a capacitor C3, one end of which is connected to pin 1 of an inductor L1, pin 2 of which is connected to pin 1 of a switch tube Q1 and one end of the capacitor C1, the other end of which is connected to pin 1 of a transformer T1, the other end of which is connected to pin 2 of the switch tube Q1 and pin 2 of the transformer T1, pin 3 of the transformer T1 is connected to pin 2 of the switch tube Q2 and one end of a capacitor C4, pin 4 of the transformer T1 is connected to one end of the capacitor C2, the other end of which is connected to pin 1 of the switch tube Q2 and pin 1 of the inductor L2, pin 2 of the inductor L2 is connected to the other end of the capacitor C4, the inductor L1 is coupled to the inductor L2, pin 1 of the inductor L1 and pin 2 of the inductor L2 are the same-named ends, and pin 1 and pin 4 of the transformer T1 are the same-named ends.

2. The high efficiency isolation circuit with low output ripple according to claim 1, characterized in that: The capacitor C3 is connected to a power source, and the capacitor C4 is connected to a load, or the capacitor C3 is connected to a load, and the capacitor C4 is connected to a power source.

3. The high efficiency isolation circuit with low output ripple according to claim 1, characterized in that: The switch tube Q1 and the switch tube Q2 are both MOS tubes, IGBTs or semiconductor switch devices.

4. The high efficiency isolation circuit with low output ripple according to claim 3, characterized in that: The gates of the switch tube Q1 and the switch tube Q2 are both connected to a drive circuit controlled by an MCU.

5. The high efficiency isolation circuit with low output ripple according to claim 1, characterized in that: Pin 1 and pin 2 of the transformer T1 share a coil, and pin 3 and pin 4 of the transformer T1 share a coil.

6. The high efficiency isolation circuit with low output ripple according to claim 1, characterized in that: The circuit is used for DCDC conversion.

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