Double-bridge converter circuit

Abstract

The invention relates to the technical field of switching power supplies, and discloses a double-bridge converter circuit, which comprises an input circuit, a switching transformer and an output circuit, and is characterized in that the input circuit further comprises a double-bridge rectifier bridge and a double-bridge negative connection circuit; according to the double-bridge converter circuit, two groups of independent direct current are rectified and output, only two switching tubes are used, compared with a full-bridge converter circuit, primary switching loss is reduced, cost and failure rate are reduced, and the double-bridge converter circuit is easy to control, fast in magnetic reset, high in conversion efficiency, stable in output and high in power.

Description

Technical Field

[0001] This invention relates to the field of switching power supply technology, and in particular to a dual-bridge converter circuit. Background Technology

[0002] Among the many switching power supply circuit topologies, the full-bridge converter circuit has many excellent performance characteristics such as good circuit symmetry, adjustable output voltage, smooth current waveform, and high conversion efficiency, which makes it widely used in the industry. However, its circuit structure has four switching transistors, which makes it more expensive, more prone to failure, more difficult to control, and more components. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a dual-bridge converter circuit. The dual-bridge converter circuit of the present invention rectifies and outputs two independent sets of DC power, and only two switching transistors are used. Compared with the full-bridge converter circuit, it reduces one stage of switching loss, lowers cost and failure rate, is easier to control, and also reduces the number of components. It has fast magnetic reset, high conversion efficiency, stable output, and high power.

[0004] The specific technical solution of the present invention is as follows: a dual bridge converter circuit, including an input circuit, a switching transformer T1, and an output circuit, wherein the input circuit further includes a dual rectifier bridge and a dual bridge negative connection circuit.

[0005] The dual-rectifier bridge consists of diodes D1, D2, D3, and D4.

[0006] The internal connection relationship of the dual-rectifier bridge is as follows: the negative terminal of diode D1 is connected to the positive terminal of diode D2 and then connected to the AC input live wire L; the positive terminal of diode D3 is connected to the negative terminal of diode D4 and then connected to the AC input neutral wire N; the positive terminal of diode D1 is connected to the first negative terminal F1-; the negative terminal of diode D2 is connected to the first positive terminal Z1+; the negative terminal of diode D3 is connected to the second positive terminal Z2+; and the positive terminal of diode D4 is connected to the second negative terminal F2-.

[0007] The negative circuit of the dual bridge consists of switching transistor Q1, switching transistor Q2, capacitor C1, capacitor C2, and primary winding W1.

[0008] The switching transformer T1 consists of a primary winding W1, a magnetic core, and a secondary winding W2.

[0009] The internal connection relationship of the dual bridge negative connection circuit is as follows: the drain of the switch Q1 is connected to the positive terminal of the capacitor C1 and then to the first positive terminal Z1+; the source of the switch Q1, the negative terminal of the capacitor C2, and the x1 terminal of the primary winding W1 are all connected to the first negative terminal F1-; the drain of the switch Q2 is connected to the positive terminal of the capacitor C2 and then to the second positive terminal Z2+; the source of the switch Q2, the negative terminal of the capacitor C1, and the x2 terminal of the primary winding W1 are all connected to the second negative terminal F2-; the gate of the switch Q1 is connected to the control signal H1; and the gate of the switch Q2 is connected to the control signal H2.

[0010] The dual-current rectifier bridge and the dual-current negative circuit of the input circuit are connected by a common terminal, namely the first positive terminal Z1+, the first negative terminal F1-, the second positive terminal Z2+, and the second negative terminal F2-, and are in a one-to-one correspondence.

[0011] The output circuit consists of a secondary winding W2, diode D5, diode D6, inductor L1, and capacitor C3.

[0012] The internal connection relationship of the output circuit is as follows: one end s1 of the secondary winding W2 is connected to the positive terminal of diode D5, the other end s2 of the secondary winding W2 is connected to the positive terminal of diode D6, the negative terminals of diode D5, diode D6, and capacitor C3 are all connected to the positive terminal OUT+ of the DC output terminal, the center tap s3 of the secondary winding W2 is connected to one end of inductor L1, and the other end of inductor L1 and the negative terminal of capacitor C3 are both connected to the negative terminal OUT- of the DC output terminal.

[0013] In this context, the x1 terminal of the primary winding W1 and the s1 terminal of the secondary winding W2 of the switching transformer T1 are terminals with the same name.

[0014] The phase difference between the control signal H1 and the control signal H2 is 180 degrees.

[0015] Wherein, the switching transistors Q1 and Q2 are NMOS field-effect transistors Q1 and Q2, respectively.

[0016] The specific working process of a dual-bridge converter circuit according to the present invention is as follows: When the AC input live wire terminal L is in the positive half-cycle of AC current, diodes D1 and D3 are cut off, and diodes D2 and D4 are turned on. The current flows through the AC input live wire terminal L → diode D2 → capacitor C1 → diode D4 → AC input neutral wire terminal N to form a charging circuit, and capacitor C1 stores energy. When the AC input live wire terminal L is in the negative half-cycle of AC current, diodes D2 and D4 are cut off, and diodes D1 and D3 are turned on. The current flows through the AC input neutral wire terminal N → diode D3 → capacitor C2 → diode D1 → AC input live wire terminal L to form a charging circuit, and capacitor C2 stores energy. When the control signal H1 is high, switch Q2 is off and switch Q1 is on. Capacitor C1 supplies power to switch transformer T1. Current flows from the positive terminal of capacitor C1 → switch Q1 → primary winding W1 → negative terminal of capacitor C1 to form a power supply circuit. The primary winding W1 generates a magnetic field, which transfers energy to the secondary winding W2 through the magnetic core of switch transformer T1. According to the principle of electromagnetic induction, a high voltage is generated at the s1 terminal of the secondary winding W2. Current flows through the s1 terminal of the secondary winding W2 → diode D5 → capacitor C3 → inductor L1 → center tap s3 of the secondary winding W2 → s1 terminal of the secondary winding W2 to form a discharge circuit. While the energy is stored and filtered through the discharge circuit, the positive terminal IN+ of the DC output terminal outputs electrical energy to the load. When the control signal H2 is high, switch Q1 is off and switch Q2 is on. Capacitor C2 supplies power to switch transformer T1. Current flows from the positive terminal of capacitor C2 → switch Q2 → primary winding W1 → negative terminal of capacitor C2 to form a power supply circuit. The primary winding W1 generates a magnetic field, which transfers energy to the secondary winding W2 through the magnetic core of switch transformer T1. According to the principle of electromagnetic induction, a high voltage is generated at the s2 terminal of the secondary winding W2. Current flows through the s2 terminal of the secondary winding W2 → diode D6 → capacitor C3 → inductor L1 → center tap s3 of the secondary winding W2 → s2 terminal of the secondary winding W2 to form a discharge circuit. While the energy is filtered and stored through the discharge circuit, the positive terminal IN+ of the DC output terminal outputs electrical energy to the load. At the instant that switch Q1 is turned off and switch Q2 is not turned on, switch transformer T1 immediately performs an automatic magnetic reset. According to the principle of back electromotive force, the voltage at the x2 terminal of the primary winding W1 increases, and the current flows through the x2 terminal of the primary winding W1 → the body diode of switch Q2 → capacitor C2 → the x1 terminal of the primary winding W1 to form a magnetic reset circuit. At the same time, the secondary winding W2 of switch transformer T2 outputs electrical energy. At the instant that switch Q2 is turned off and switch Q1 is not conducting, switch transformer T1 immediately performs an automatic magnetic reset. According to the principle of back electromotive force, the voltage at the x1 terminal of the primary winding W1 increases, and the current flows through the x1 terminal of the primary winding W1 → the body diode of switch Q1 → capacitor C1 → the x2 terminal of the primary winding W1 to form a magnetic reset circuit. At the same time, the secondary winding W2 of switch transformer T2 outputs electrical energy.

[0017] Preferably, the switching transistors Q1 and Q2 are IGBT insulated gate bipolar transistors Q1 and Q2, respectively.

[0018] Preferably, the switching transistors Q1 and Q2 are SiC field-effect transistors Q1 and Q2, respectively.

[0019] The beneficial effects of this invention are as follows: The present invention discloses a dual-bridge converter circuit that rectifies and outputs two independent DC currents. It uses only two switching transistors. Compared with the full-bridge converter circuit, it reduces one stage of switching loss, lowers cost and failure rate, is easier to control, and also reduces the number of components. It has fast magnetic reset, high conversion efficiency, stable output, and high power. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a dual-bridge converter circuit according to the present invention; Figure 2 This is a schematic diagram of the voltage waveforms of control signal H1, control signal H2, drain of switching transistor Q1, and drain of switching transistor Q2 in this invention. Detailed Implementation

[0021] The technology of the present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0022] like Figure 1 As shown, a dual-bridge converter circuit includes an input circuit, a switching transformer T1, and an output circuit. The input circuit further includes a dual-rectifier bridge and a dual-bridge negative connection circuit. The dual-rectifier bridge is composed of diodes D1, D2, D3, and D4. The internal connection relationship of the dual rectifier bridge is as follows: the negative terminal of diode D1 is connected to the positive terminal of diode D2 and then connected to the AC input live wire L; the positive terminal of diode D3 is connected to the negative terminal of diode D4 and then connected to the AC input neutral wire N; the positive terminal of diode D1 is connected to the first negative terminal F1-; the negative terminal of diode D2 is connected to the first positive terminal Z1+; the negative terminal of diode D3 is connected to the second positive terminal Z2+; and the positive terminal of diode D4 is connected to the second negative terminal F2-. The negative connection circuit of the dual bridge consists of switching transistor Q1, switching transistor Q2, capacitor C1, capacitor C2, and primary winding W1. The switching transformer T1 consists of a primary winding W1, a magnetic core, and a secondary winding W2; The internal connection relationship of the dual bridge negative connection circuit is as follows: the drain of the switch Q1 is connected to the positive terminal of the capacitor C1 and then to the first positive terminal Z1+; the source of the switch Q1, the negative terminal of the capacitor C2, and the x1 terminal of the primary winding W1 are all connected to the first negative terminal F1-; the drain of the switch Q2 is connected to the positive terminal of the capacitor C2 and then to the second positive terminal Z2+; the source of the switch Q2, the negative terminal of the capacitor C1, and the x2 terminal of the primary winding W1 are all connected to the second negative terminal F2-; the gate of the switch Q1 is connected to the control signal H1; and the gate of the switch Q2 is connected to the control signal H2. Among them, the dual-current rectifier bridge and the dual-current bridge negative connection circuit of the input circuit are connected by the first positive terminal Z1+, the first negative terminal F1-, the second positive terminal Z2+, and the second negative terminal F2- as common terminals, and correspond one-to-one. The output circuit consists of a secondary winding W2, a diode D5, a diode D6, an inductor L1, and a capacitor C3. The internal connection relationship of the output circuit is as follows: one end s1 of the secondary winding W2 is connected to the positive terminal of diode D5, the other end s2 of the secondary winding W2 is connected to the positive terminal of diode D6, the negative terminals of diode D5, diode D6, and capacitor C3 are all connected to the positive terminal OUT+ of the DC output terminal, the center tap s3 of the secondary winding W2 is connected to one end of inductor L1, and the other end of inductor L1 and the negative terminal of capacitor C3 are all connected to the negative terminal OUT- of the DC output terminal. In this embodiment, the x1 terminal of the primary winding W1 and the s1 terminal of the secondary winding W2 of the switching transformer T1 are terminals with the same name. In this embodiment, the phase difference between the control signal H1 and the control signal H2 is 180 degrees; In this embodiment, the switching transistors Q1 and Q2 are NMOS field-effect transistors Q1 and Q2, respectively; The specific working process of a dual-bridge converter circuit according to the present invention is as follows: like Figure 1 As shown, when the AC input live wire terminal L is in the positive half-cycle of AC current, diodes D1 and D3 are cut off, while diodes D2 and D4 are turned on. The current flows through the AC input live wire terminal L → diode D2 → capacitor C1 → diode D4 → AC input neutral wire terminal N to form a charging circuit, and capacitor C1 stores energy. When the AC input live wire terminal L is in the negative half-cycle of AC current, diodes D2 and D4 are cut off, and diodes D1 and D3 are turned on. The current flows through the AC input neutral wire terminal N → diode D3 → capacitor C2 → diode D1 → AC input live wire terminal L to form a charging circuit, and capacitor C2 stores energy. like Figure 2As shown, during the time period from t1 to t2, the control signal H1 is at a high level, the switch Q2 is turned off and the switch Q1 is turned on. The capacitor C1 supplies power to the switching transformer T1. The current flows out from the positive terminal of the capacitor C1 → switch Q1 → primary winding W1 → negative terminal of the capacitor C1 to form a power supply circuit. The primary winding W1 is energized and generates a magnetic field, which transfers energy to the secondary winding W2 through the magnetic core of the switching transformer T1. According to the principle of electromagnetic induction, a high voltage is generated at the s1 terminal of the secondary winding W2. The current flows through the s1 terminal of the secondary winding W2 → diode D5 → capacitor C3 → inductor L1 → center tap s3 of the secondary winding W2 → s1 terminal of the secondary winding W2 to form a discharge circuit. While the energy is filtered and stored through the discharge circuit, the positive terminal IN+ of the DC output terminal outputs electrical energy to the load. During the time interval from t3 to t4, control signal H2 is at a high level, switch Q1 is turned off and switch Q2 is turned on. Capacitor C2 supplies power to switching transformer T1. Current flows out from the positive terminal of capacitor C2 → switch Q2 → primary winding W1 → negative terminal of capacitor C2 to form a power supply circuit. The primary winding W1 is energized and generates a magnetic field, which transfers energy to the secondary winding W2 through the magnetic core of switching transformer T1. According to the principle of electromagnetic induction, a high voltage is generated at the s2 terminal of the secondary winding W2. Current flows through the s2 terminal of the secondary winding W2 → diode D6 → capacitor C3 → inductor L1 → center tap s3 of the secondary winding W2 → s2 terminal of the secondary winding W2 to form a discharge circuit. While the energy is filtered and stored through the discharge circuit, the positive terminal IN+ of the DC output terminal outputs electrical energy to the load. During the time interval from t2 to t3, switch Q1 is turned off and switch Q2 is not turned on, so switch transformer T1 immediately performs an automatic magnetic reset. According to the principle of back electromotive force, the voltage at the x2 terminal of the primary winding W1 increases, and the current flows through the x2 terminal of the primary winding W1 → the body diode of switch Q2 → capacitor C2 → the x1 terminal of the primary winding W1 to form a magnetic reset circuit. At the same time, the secondary winding W2 of switch transformer T2 outputs electrical energy. During the time interval from t4 to t5, switch Q2 is turned off and switch Q1 is not turned on, so switch transformer T1 immediately performs an automatic magnetic reset. According to the principle of back electromotive force, the voltage at the x1 terminal of the primary winding W1 increases, and the current flows through the x1 terminal of the primary winding W1 → the body diode of switch Q1 → capacitor C1 → the x2 terminal of the primary winding W1 to form a magnetic reset circuit. At the same time, the secondary winding W2 of switch transformer T2 outputs electrical energy. Example

[0023] The difference between Example 2 and Example 1 is that: The switching transistors Q1 and Q2 are IGBT insulated gate bipolar transistors Q1 and Q2, respectively. Example

[0024] The difference between Example 3 and Example 1 is that: The switching transistors Q1 and Q2 are SiC field-effect transistors Q1 and Q2, respectively.

[0025] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A dual-bridge converter circuit, comprising an input circuit, a switching transformer T1, and an output circuit, characterized in that: The input circuit also includes a dual-current rectifier bridge and a dual-current bridge negative connection circuit; The dual-rectifier bridge is composed of diodes D1, D2, D3, and D4. The internal connection relationship of the dual rectifier bridge is as follows: the negative terminal of diode D1 is connected to the positive terminal of diode D2 and then connected to the AC input live wire L; the positive terminal of diode D3 is connected to the negative terminal of diode D4 and then connected to the AC input neutral wire N; the positive terminal of diode D1 is connected to the first negative terminal F1-; the negative terminal of diode D2 is connected to the first positive terminal Z1+; the negative terminal of diode D3 is connected to the second positive terminal Z2+; and the positive terminal of diode D4 is connected to the second negative terminal F2-. The negative connection circuit of the dual bridge consists of switching transistor Q1, switching transistor Q2, capacitor C1, capacitor C2, and primary winding W1. The switching transformer T1 consists of a primary winding W1, a magnetic core, and a secondary winding W2; The internal connection relationship of the dual bridge negative connection circuit is as follows: the drain of the switch Q1 is connected to the positive terminal of the capacitor C1 and then to the first positive terminal Z1+; the source of the switch Q1, the negative terminal of the capacitor C2, and the x1 terminal of the primary winding W1 are all connected to the first negative terminal F1-; the drain of the switch Q2 is connected to the positive terminal of the capacitor C2 and then to the second positive terminal Z2+; the source of the switch Q2, the negative terminal of the capacitor C1, and the x2 terminal of the primary winding W1 are all connected to the second negative terminal F2-; the gate of the switch Q1 is connected to the control signal H1; and the gate of the switch Q2 is connected to the control signal H2. Among them, the dual-current rectifier bridge and the dual-current bridge negative connection circuit of the input circuit are connected by the first positive terminal Z1+, the first negative terminal F1-, the second positive terminal Z2+, and the second negative terminal F2- as common terminals, and correspond one-to-one. The output circuit consists of a secondary winding W2, a diode D5, a diode D6, an inductor L1, and a capacitor C3. Wherein, the x1 terminal of the primary winding W1 and the s1 terminal of the secondary winding W2 of the switching transformer T1 are terminals with the same name; The phase difference between the control signal H1 and the control signal H2 is 180 degrees. Wherein, the switching transistors Q1 and Q2 are NMOS field-effect transistors Q1 and Q2, respectively.

2. The dual-bridge converter circuit as described in claim 1, characterized in that, The switching transistors Q1 and Q2 are IGBT insulated gate bipolar transistors Q1 and Q2, respectively.

3. The dual-bridge converter circuit as described in claim 1, characterized in that, The switching transistors Q1 and Q2 are SiC field-effect transistors Q1 and Q2, respectively.

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