Staggered series LLC power topological structure suitable for 540V power supply input

Abstract

The utility model discloses an interleaved series LLC power topological structure suitable for 540V power supply input, comprising an LLC conversion circuit assembly, two synchronous rectification circuits and an output load, the LLC conversion circuit assembly is composed of a first LLC conversion circuit and a second LLC conversion circuit which are connected in series, and a PI control circuit, the PI control circuit is provided with a voltage control loop and a current loop; according to the utility model, the use cost of devices can be reduced, an LLC structure is adopted, input voltage-sharing control of soft switching and two paths of full-bridge LLC can be realized, an interleaving control mode is adopted, output ripples are reduced, the power density can be improved, the requirements of high-voltage input and high-power density are met, and the high-voltage input circuit is suitable for high-voltage input occasions.

Description

Technical Field

[0001] The utility model relates to the technical field of DC / DC converter LLC power, and particularly to an interleaved series LLC power topology suitable for 540V power supply input. Background Art

[0002] With the development of power electronics technology, in order to obtain higher conversion efficiency and power density, high-voltage and high-current power supply systems have been widely used in airborne equipment. In order to meet the converter functions and performance of high-voltage input and high-current output in the airborne power supply system, traditional topologies are either difficult to meet the requirements of high-voltage input and high-current output occasions or difficult to achieve high power density. Content of the Utility Model

[0003] The purpose of the utility model is to provide an interleaved series LLC power topology suitable for 540V power supply input, so as to solve the problem that traditional topologies are difficult to meet the requirements of high-voltage input and high-current output occasions in the above-mentioned background art.

[0004] To achieve the above purpose, the utility model provides the following technical solution: An interleaved series LLC power topology suitable for 540V power supply input, including an LLC conversion circuit component, two-way synchronous rectification circuits and an output load. The LLC conversion circuit component is composed of a first LLC conversion circuit and a second LLC conversion circuit connected in series, and a PI control circuit. The output end of the first LLC conversion circuit is connected to one-way synchronous rectification circuit, and the output end of the second LLC conversion circuit is connected to the other-way synchronous rectification circuit. Moreover, the input end of the LLC conversion circuit component is connected to the power supply end through a full-bridge tube component, and a voltage-sharing capacitor component and a voltage-sharing resistor component are arranged between the full-bridge tube component and the power supply end. The PI control circuit has two parts: a voltage control loop and a current loop. The voltage control loop is used to collect the output voltage to generate a voltage control signal, and the current loop is used to collect the output current to generate a current control signal. A voltage-controlled oscillator is connected to the output ends of the current loop and the voltage control loop.

[0005] Further, the full-bridge tube component includes four groups of full-bridge tubes S1-S4 connected to the first LLC conversion circuit and four groups of full-bridge tubes S5-S8 connected to the second LLC conversion circuit. The full-bridge tube component is used to receive the output frequency control signal of the voltage-controlled oscillator.

[0006] Further, the synchronous rectification circuit includes four groups of rectifier tubes Q1-Q4. The rectifier tube Q1 and the rectifier tube Q2 are connected to the first LLC conversion circuit, and the rectifier tube Q3 and the rectifier tube Q4 are connected to the second LLC conversion circuit.

[0007] Further, the voltage-sharing capacitor assembly is composed of a capacitor C1 and a capacitor C2. The capacitor C1 and the capacitor C2 are connected in series. The capacitor C1 is connected to the first LLC conversion circuit, and the capacitor C2 is connected to the second LLC conversion circuit.

[0008] Further, the voltage-sharing resistor assembly includes a resistor R1 and a resistor R2 connected to the first LLC conversion circuit, and a resistor R3 and a resistor R4 connected to the second LLC conversion circuit.

[0009] The beneficial effects of the present utility model are as follows: The present utility model can reduce the voltage stress of the input switching tube, reduce the usage cost of the device, enable it to adapt to high-voltage input occasions, and adopt the LLC structure, which can realize soft switching and input voltage sharing control of two full-bridge LLCs, thereby reducing the switching loss of the full-bridge tube or the rectifier tube and improving the conversion efficiency of the converter; at the same time, the interleaved control method is adopted to reduce the output ripple while improving the power density, meeting the requirements of high-voltage input and high power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the interleaved series LLC power topology structure of the present utility model.

[0011] In the figure: 1 is the first LLC conversion circuit, 2 is the second LLC conversion circuit, and 3 is the output load. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0013] Please refer to Figure 1 , which provides a technical solution for the present utility model, an interleaved series LLC power topology structure suitable for a 540V power supply input, including an LLC conversion circuit assembly, two synchronous rectification circuits, and an output load 3. The LLC conversion circuit assembly is composed of a series-connected first LLC conversion circuit 1 and a second LLC conversion circuit 2, and a PI control circuit. The output end of the first LLC conversion circuit 1 is connected to one synchronous rectification circuit, and the output end of the second LLC conversion circuit 2 is connected to the other synchronous rectification circuit. The input end of the LLC conversion circuit assembly is connected to the power supply end through a full-bridge tube assembly. The power supply end is marked with Vdc, and the power supply end inputs 540V high voltage; a voltage-sharing capacitor assembly and a voltage-sharing resistor assembly are provided between the full-bridge tube assembly and the power supply end.

[0014] In this embodiment, the synchronous rectification circuit includes four groups of rectifier diodes Q1 - Q4. These four groups of rectifier diodes Q1 - Q4 form a synchronous rectification circuit. Rectifier diode Q1 and rectifier diode Q2 are connected to the first LLC conversion circuit 1, and rectifier diodes Q3 and Q4 are connected to the second LLC conversion circuit 2. Rectifier diodes Q3 and Q4 form another synchronous rectification circuit.

[0015] It should be noted that the voltage equalizing capacitor assembly is composed of capacitor C1 and capacitor C2. Capacitor C1 and capacitor C2 are connected in series. Capacitor C1 is connected to the first LLC conversion circuit 1, and capacitor C2 is connected to the second LLC conversion circuit 2. The voltage equalizing resistor assembly includes resistor R1 and resistor R2 connected to the first LLC conversion circuit 1, and resistor R3 and resistor R4 connected to the second LLC conversion circuit 2.

[0016] In this embodiment, the mentioned PI control circuit has two parts: a voltage control loop and a current loop. The voltage control loop is used to collect the output voltage to generate a voltage control signal, and the current loop is used to collect the output current to generate a current control signal. A voltage - controlled oscillator is connected to the output ends of the current loop and the voltage control loop.

[0017] In this embodiment, the mentioned full - bridge tube assembly includes four groups of full - bridge tubes S1 - S4 connected to the first LLC conversion circuit 1 and four groups of full - bridge tubes S5 - S8 connected to the second LLC conversion circuit 2. The full - bridge tube assembly is used to receive the output frequency control signal of the voltage - controlled oscillator.

[0018] The interleaved series LLC power topology applicable to a 540V power supply input has a 540V high voltage connected to the power supply end. The first LLC conversion circuit 1 and the second LLC conversion circuit 2 are connected in series for LLC input. Thus, the input voltage of each LLC is 270V, and the voltage stress borne by each tube is 270V / 2. The mentioned PI control circuit realizes the control of the output voltage of the LLC conversion circuit, making the output voltage stable at about 29V. The voltage control loop collects the output voltage, compares it with the reference voltage, and obtains the corresponding voltage control signal through PI control. The current control loop collects the output current, compares it with the reference current, and obtains the corresponding current control signal through PI control. Then, by comparing the voltage control signal and the current control signal and taking the smallest control signal to enter the voltage-controlled oscillator to output a frequency control signal, a corresponding drive signal is generated to drive the full-bridge tubes S1, S2, S3, S4, S5, S6, S7, S8 and the rectifier tubes Q1, Q2, Q3, Q4 to act, realizing the control of the LLC conversion circuit. The voltage-controlled oscillator is marked with VCO. Among them, the control signal sent by the PI control circuit generates a drive signal to drive the conduction and cut-off of the rectifier tubes Q1, Q2, Q3, Q4, realizing the conversion of the LLC conversion circuit. Among them, the PI control circuit mainly processes and controls the collected voltage and current signals and then outputs the corresponding control signals.

[0019] It should be noted that the current loop only works when the output current is relatively large. Because when the output current Io is small, the output voltage Vo is relatively large, and the voltage control signal adjusted by the current loop and the voltage control loop is relatively small. At this time, only the voltage control loop works. On the contrary, when the output current Io is large, the current loop works.

[0020] To sum up: The interleaved series LLC power topology applicable to a 540V power supply input can achieve a high voltage input of 540V - 700V and a stable output of 29V. The efficiency of the converter applying this interleaved series LLC power topology can reach over 96%.

[0021] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as within the scope described in this specification.

[0022] The above embodiments only represent the preferred embodiments of the present utility model. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all fall within the protection scope of the present utility model. In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. Among them, there are various ways of detachable installation. For example, it can be by the way of cooperation between plugging and buckling, or by the way of bolt connection, etc.

[0023] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. An interleaved series LLC power topology suitable for a 540V power supply input, characterized in that: It includes an LLC conversion circuit component, two-way synchronous rectification circuits, and an output load. The LLC conversion circuit component is composed of a first LLC conversion circuit and a second LLC conversion circuit connected in series, and a PI control circuit. The output end of the first LLC conversion circuit is connected to one of the synchronous rectification circuits, and the output end of the second LLC conversion circuit is connected to the other synchronous rectification circuit. The input end of the LLC conversion circuit component is connected to the power supply end through a full-bridge tube component, and a voltage-sharing capacitor component and a voltage-sharing resistor component are provided between the full-bridge tube component and the power supply end. The PI control circuit has two parts: a voltage control loop and a current loop. The voltage control loop is used to collect the output voltage to generate a voltage control signal, and the current loop is used to collect the output current to generate a current control signal. A voltage-controlled oscillator is connected to the output ends of the current loop and the voltage control loop.

2. The interleaved series LLC power topology applicable to a 540V power supply input according to claim 1, wherein: The full-bridge tube component includes four groups of full-bridge tubes S1-S4 connected to the first LLC conversion circuit and four groups of full-bridge tubes S5-S8 connected to the second LLC conversion circuit. The full-bridge tube component is used to receive the output frequency control signal of the voltage-controlled oscillator.

3. An interleaved series LLC power topology suitable for 540V power supply input according to claim 1, characterized in that: The synchronous rectification circuit includes four groups of rectifier tubes Q1-Q4. The rectifier tube Q1 and the rectifier tube Q2 are connected to the first LLC conversion circuit, and the rectifier tube Q3 and the rectifier tube Q4 are connected to the second LLC conversion circuit.

4. A interleaved series LLC power topology applicable to a 540V power supply input according to claim 1, characterized in that: The voltage-sharing capacitor component is composed of a capacitor C1 and a capacitor C2. The capacitor C1 and the capacitor C2 are connected in series, and the capacitor C1 is connected to the first LLC conversion circuit, and the capacitor C2 is connected to the second LLC conversion circuit.

5. A staggered series LLC power topology applicable to a 540V power supply input, characterized in that: The voltage-sharing resistor component includes a resistor R1 and a resistor R2 connected to the first LLC conversion circuit, and a resistor R3 and a resistor R4 connected to the second LLC conversion circuit.

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