Anti-surge current bidirectional CLLLC resonant converter structure

Abstract

The utility model relates to the technical field of power electronics, in particular to an anti-surge current bidirectional CLLLC resonant converter structure, which comprises a bidirectional converter and suppression modules symmetrically arranged at two ends of the bidirectional converter. According to the utility model, the boost speed of the current in the circuit is slowed down by the input resistance-capacitance circuit, so that the bidirectional converter is prevented from being influenced by the large current of the circuit during the starting period, the bidirectional converter performs conversion processing on the input current and then outputs the current through the output suppression circuit, and when the bidirectional converter is turned off, the output suppression circuit is switched off. The output suppression circuit can suppress a surge circuit generated in the circuit, thereby preventing the bidirectional converter from being damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to a bidirectional CLLLC resonant converter structure for preventing surge current. Background Art

[0002] The bidirectional CLLLC resonant converter consists of two CLLLC resonant circuits, which are used to realize power flow in two directions. Its basic principle is to use the characteristics of the resonant circuit to realize zero voltage switching (ZVS) and zero current switching (ZCS) in the process of power conversion, thereby improving the conversion efficiency.

[0003] For example, CN115642809A involves a bidirectional CLLC resonant circuit structure using a dual transformer, including: a primary bridge, a secondary bridge, a primary-secondary resonant capacitor, and two transformers connected in series with the primary and secondary sides respectively, and the turns ratio and excitation inductance of the two transformers are variable; wherein the first transformer has opposite same-name ends or same-name ends in the same direction, and the same-name ends of the second transformer are in the same direction; relative to the conventional bidirectional CLLC resonant circuit structure, the circuit structure uses two series transformers to equivalently replace the transformer in the original resonant cavity and the two discrete resonant inductors located at the primary and secondary sides. The present invention effectively reduces the volume and number of magnetic components in the circuit, optimizes the power density of the CLLC converter, and the transmission power and volume of the two transformers can be adjusted by adjusting the turns ratio and the excitation inductance. However, during the startup of the CLLC converter, because the current flowing into the converter will quickly charge the large-capacity capacitor, a peak current far greater than the steady-state input current of the normal operation of the circuit is generated, that is, a surge current, which will affect the normal operation of the CLLC converter.

[0004] In order to reduce the impact of surge current on the CLLC converter, a surge current-proof bidirectional CLLC resonant converter structure is proposed. Utility Model Content

[0005] The utility model aims to provide a bidirectional CLLLC resonant converter structure for preventing surge current, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the utility model provides a bidirectional CLLLC resonant converter structure for surge current prevention, comprising a bidirectional converter and a suppression module symmetrically arranged at both ends of the bidirectional converter, wherein the suppression module comprises an input resistor-capacitor circuit and an output suppression circuit, wherein the input resistor-capacitor circuit is connected to the bidirectional converter, and the bidirectional converter is connected to the output suppression circuit;

[0007] The bidirectional converter receives current through the input RC circuit and outputs it through the output suppression circuit, wherein the input RC circuit is used to reduce the current boost speed of the bidirectional converter startup device, and the output suppression circuit is used to suppress the reverse current generated in the circuit when the bidirectional converter is turned off.

[0008] As a further improvement of the technical solution, the input resistance-capacitance circuit includes a chip U1 and a transistor Q1, wherein:

[0009] The VI terminal of the chip U1 is connected to the capacitor C1, the VO terminal is connected to the diodes D1 and D2 in parallel with the resistor R2, the ADJ terminal is connected to the resistors R1 and R3, the collector of the transistor Q1 is connected in parallel with the other end of the resistor R2, and the diode D2 is connected to the A terminal;

[0010] The base of the transistor Q1 is connected to the capacitor C2 and is connected to the other end of the diode D1 and the other end of the resistor R3. The emitter of the transistor Q1 is connected to the other end of the capacitor C1, the other end of C2, the other end of the resistor R1 and is connected to the diode D3. The diode D3 is connected to the B end.

[0011] As a further improvement of the technical solution, the output suppression circuit includes inductors L1 and L2, wherein:

[0012] One end of the inductor L1 is connected to the C end, the other end of the inductor L1 is connected to the capacitor C3 and connected to the diode D4, the capacitor C3 is connected to the capacitor C4 and is grounded;

[0013] One end of the inductor L2 is connected to the D end, and the other end of the inductor L2 is connected to the diode D5 and connected to the other end of the capacitor C4.

[0014] As a further improvement of the technical solution, the bidirectional converter includes a transformer and a switch module symmetrically arranged at both ends of the transformer, the switch module includes switch tubes ST1, ST2, ST3, ST4 arranged on one side of the transformer and switch tubes SV1, SV2, SV3, SV4 on the other side of the transformer, and the transformer connects the switch tubes ST1, ST2, ST3, ST4, SV1, SV2, SV3, SV4;

[0015] The switch tubes ST1 and ST4 are connected to the A and C terminals, and the switch tubes ST2 and ST3 are connected to the B and D terminals;

[0016] Similarly, the switch tubes SV1 and SV4 are both connected to the A and C terminals, and the switch tubes SV2 and SV3 are both connected to the B and D terminals.

[0017] As a further improvement of this technical solution,

[0018] The switch tube ST1 is connected in parallel with a diode D11 and a capacitor C11, the switch tube ST2 is connected in parallel with a diode D12 and a capacitor C12, the switch tube ST3 is connected in parallel with a diode D13 and a capacitor C13, and the switch tube ST4 is connected in parallel with a diode D14 and a capacitor C14;

[0019] The switch tube SV1 is connected in parallel with a diode D15 and a capacitor C15, the switch tube SV2 is connected in parallel with a diode D16 and a capacitor C16, the switch tube SV3 is connected in parallel with a diode D17 and a capacitor C17, and the switch tube SV4 is connected in parallel with a diode D18 and a capacitor C18.

[0020] As a further improvement of the present technical solution, the transformer is a hollow transformer.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] In the surge current-proof bidirectional CLLLC resonant converter structure, the input resistor-capacitor circuit slows down the voltage rise speed of the current in the circuit, thereby preventing the bidirectional converter from being affected by the large current of the circuit during startup. After the bidirectional converter converts the input current, it outputs it through the output suppression circuit. When the bidirectional converter is turned off, the output suppression circuit can suppress the surge current generated in the circuit, thereby preventing the bidirectional converter from being damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0024] Figure 2 This is the input resistance-capacitance circuit diagram of the utility model;

[0025] Figure 3 This is the output suppression circuit diagram of the utility model;

[0026] Figure 4 This is a circuit diagram of a bidirectional converter of the utility model. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] See also Figure 1-Figure 4As shown, this embodiment provides a bidirectional CLLLC resonant converter structure for surge current protection, including a bidirectional converter and a suppression module symmetrically arranged at both ends of the bidirectional converter, the suppression module includes an input resistor-capacitor circuit and an output suppression circuit, the input resistor-capacitor circuit is connected to the bidirectional converter, and the bidirectional converter is connected to the output suppression circuit;

[0029] The bidirectional converter receives current through an input resistor-capacitor circuit and outputs it through an output suppression circuit, wherein the input resistor-capacitor circuit is used to reduce the current boost speed of the bidirectional converter startup device, and the output suppression circuit is used to suppress the reverse current generated in the circuit when the bidirectional converter is turned off.

[0030] Principle: When an external power source is connected to a bidirectional converter through an input RC circuit, the input RC circuit slows down the voltage rise speed of the current in the circuit, thereby preventing the bidirectional converter from being affected by the large current of the circuit during startup. After the bidirectional converter converts the input current, it outputs it through the output suppression circuit. When the bidirectional converter is turned off, the output suppression circuit can suppress the surge current generated in the circuit, thereby preventing the bidirectional converter from being damaged.

[0031] The input resistor-capacitor circuit includes chip U1 and transistor Q1, where:

[0032] The VI terminal of chip U1 is connected to capacitor C1, the VO terminal is connected to diodes D1 and D2 in parallel with resistor R2, the ADJ terminal is connected to resistors R1 and R3, the collector of transistor Q1 is connected in parallel with the other end of resistor R2, and the diode D2 is connected to terminal A;

[0033] The base of transistor Q1 is connected to capacitor C2 and is connected to the other end of diode D1 and the other end of resistor R3. The emitter of transistor Q1 is connected to the other end of capacitor C1, the other end of C2, the other end of resistor R1 and is connected to diode D3. Diode D3 is connected to terminal B.

[0034] In this circuit, chip U1 is the power integrated circuit LM317. The combination of transistor Q1 and capacitor C2 helps the circuit gradually increase the output voltage. Diodes D2 and D3 are used as unidirectional current-limiting resistors to limit the current so that it can only enter the bidirectional converter from the input resistor-capacitor circuit. As the voltage across capacitor C2 increases, the circuit voltage rises at the same rate and reaches the required output voltage set by the resistor. When the output voltage reaches the required value, transistor Q1 will be turned off to reduce the surge current, thereby increasing the durability of the device.

[0035] The output suppression circuit includes inductors L1 and L2, where:

[0036] One end of the inductor L1 is connected to the C end, the other end of the inductor L1 is connected to the capacitor C3 and connected to the diode D4, the capacitor C3 is connected to the capacitor C4 and is grounded;

[0037] One end of the inductor L2 is connected to the D end, and the other end of the inductor L2 is connected to the diode D5 and connected to the other end of the capacitor C4.

[0038] Diodes D4 and D5 are used as a unidirectional current limiting circuit to limit the current to only flow out of the bidirectional converter through the output suppression circuit. Inductors L1 and L2 are used as common-mode inductors to suppress the induced surge current generated in the circuit during the shutdown period of the bidirectional converter.

[0039] The bidirectional converter includes a transformer and a switch module symmetrically arranged at both ends of the transformer, the switch module includes switch tubes ST1, ST2, ST3, ST4 arranged on one side of the transformer and switch tubes SV1, SV2, SV3, SV4 arranged on the other side of the transformer, and the transformer connects the switch tubes ST1, ST2, ST3, ST4, SV1, SV2, SV3, SV4;

[0040] The switch tubes ST1 and ST4 are connected to the A and C terminals, and the switch tubes ST2 and ST3 are connected to the B and D terminals;

[0041] Similarly, the switch tubes SV1 and SV4 are connected to the A and C terminals, and the switch tubes SV2 and SV3 are connected to the B and D terminals;

[0042] The switch tube ST1 is connected in parallel with a diode D11 and a capacitor C11, the switch tube ST2 is connected in parallel with a diode D12 and a capacitor C12, the switch tube ST3 is connected in parallel with a diode D13 and a capacitor C13, and the switch tube ST4 is connected in parallel with a diode D14 and a capacitor C14;

[0043] The switch tube SV1 is connected in parallel with a diode D15 and a capacitor C15, the switch tube SV2 is connected in parallel with a diode D16 and a capacitor C16, the switch tube SV3 is connected in parallel with a diode D17 and a capacitor C17, the switch tube SV4 is connected in parallel with a diode D18 and a capacitor C18, the side where the switch tubes ST1, ST2, ST3, and ST4 are located is the primary side of the bidirectional converter, and the side where the switch tubes SV1, SV2, SV3, and SV4 are located is the secondary side of the bidirectional converter. In the bidirectional converter, inversion is performed through a switch module, and energy is transferred from the primary side to the secondary side through a transformer.

[0044] Among them, the transformer is a hollow transformer, which uses the resonance between hollow capacitors and inductors to achieve electrical energy conversion. It has high energy transmission efficiency and can achieve higher power density due to the absence of core saturation and magnetic loss.

[0045] The present embodiment is a bidirectional CLLC resonant converter structure for surge current prevention. When used in practice, when an external power supply is input to a resistor-capacitor circuit, diodes D2 and D3 are used as unidirectional current limiting resistors to limit the current to only enter the bidirectional converter from the input resistor-capacitor circuit, and the combination of transistor Q1 and capacitor C2 helps to slow down the voltage rise speed of the current in the circuit, thereby preventing the bidirectional converter from being affected by the large current of the circuit during startup. After the bidirectional converter converts the input current, it outputs it through an output suppression circuit, and diodes D4 and D5 are used as unidirectional current limiting circuits to limit the current to only flow out of the bidirectional converter through the output suppression circuit. When the bidirectional converter is turned off, inductors L1 and L2 are used as common-mode inductors to suppress the induced surge current generated in the circuit, thereby preventing the bidirectional converter from being damaged.

[0046] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A bidirectional CLLLC resonant converter structure for surge current protection, characterized in that: It includes a bidirectional converter and a suppression module symmetrically arranged at both ends of the bidirectional converter, the suppression module includes an input resistor-capacitor circuit and an output suppression circuit, the input resistor-capacitor circuit is connected to the bidirectional converter, and the bidirectional converter is connected to the output suppression circuit; The bidirectional converter receives current through the input RC circuit and outputs it through the output suppression circuit, wherein the input RC circuit is used to reduce the current boost speed of the bidirectional converter startup device, and the output suppression circuit is used to suppress the reverse current generated in the circuit when the bidirectional converter is turned off.

2. The bidirectional CLLLC resonant converter structure for surge current protection according to claim 1, characterized in that: The input resistance-capacitance circuit includes a chip U1 and a transistor Q1, wherein: The VI terminal of the chip U1 is connected to the capacitor C1, the VO terminal is connected to the diodes D1 and D2 in parallel with the resistor R2, the ADJ terminal is connected to the resistors R1 and R3, the collector of the transistor Q1 is connected in parallel with the other end of the resistor R2, and the diode D2 is connected to the A terminal; The base of the transistor Q1 is connected to the capacitor C2 and is connected to the other end of the diode D1 and the other end of the resistor R3. The emitter of the transistor Q1 is connected to the other end of the capacitor C1, the other end of C2, the other end of the resistor R1 and is connected to the diode D3. The diode D3 is connected to the B end.

3. The bidirectional CLLLC resonant converter structure for surge current protection according to claim 2, characterized in that: The output suppression circuit includes inductors L1 and L2, wherein: One end of the inductor L1 is connected to the C end, the other end of the inductor L1 is connected to the capacitor C3 and connected to the diode D4, the capacitor C3 is connected to the capacitor C4 and is grounded; One end of the inductor L2 is connected to the D end, and the other end of the inductor L2 is connected to the diode D5 and connected to the other end of the capacitor C4.

4. The bidirectional CLLLC resonant converter structure for surge current protection according to claim 1, characterized in that: The bidirectional converter includes a transformer and a switch module symmetrically arranged at both ends of the transformer, the switch module includes switch tubes ST1, ST2, ST3, ST4 arranged on one side of the transformer and switch tubes SV1, SV2, SV3, SV4 arranged on the other side of the transformer, and the transformer is connected to the switch tubes ST1, ST2, ST3, ST4, SV1, SV2, SV3, SV4; The switch tubes ST1 and ST4 are connected to the A and C terminals, and the switch tubes ST2 and ST3 are connected to the B and D terminals; Similarly, the switch tubes SV1 and SV4 are both connected to the A and C terminals, and the switch tubes SV2 and SV3 are both connected to the B and D terminals.

5. The bidirectional CLLLC resonant converter structure for surge current protection according to claim 4, characterized in that: The switch tube ST1 is connected in parallel with a diode D11 and a capacitor C11, the switch tube ST2 is connected in parallel with a diode D12 and a capacitor C12, the switch tube ST3 is connected in parallel with a diode D13 and a capacitor C13, and the switch tube ST4 is connected in parallel with a diode D14 and a capacitor C14; The switch tube SV1 is connected in parallel with a diode D15 and a capacitor C15, the switch tube SV2 is connected in parallel with a diode D16 and a capacitor C16, the switch tube SV3 is connected in parallel with a diode D17 and a capacitor C17, and the switch tube SV4 is connected in parallel with a diode D18 and a capacitor C18.

6. The bidirectional CLLLC resonant converter structure for surge current protection according to claim 4, characterized in that: The transformer is an air-core transformer.

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