Direct-current conversion power supply based on three-phase staggered Buck topology circuit

Abstract

The invention discloses a direct-current conversion power supply based on a three-phase staggered Buck topology circuit, which comprises an input line, a Buck circuit, an output line and a control unit, and is characterized in that the input end of the Buck circuit is connected with the input line, the output end of the Buck circuit is connected with the output line, and the Buck circuit and the control unit form a double-closed-loop control system; according to the invention, the input and output ripples of the direct-current power supply can be reduced, the conversion efficiency and the power density can be improved, the wide-range input voltage can be converted into stable 270V direct current, power can be directly supplied to onboard electric equipment or the stable 270V direct current can be converted into other direct current through secondary conversion, and the power supply structure requirements of high power density, high conversion efficiency and modularization are met.

Description

Technical Field

[0001] The invention relates to the field of direct current power supplies, and in particular to a direct current conversion power supply based on a three-phase interleaved Buck topology circuit. Background Art

[0002] A DC power supply is a device that maintains a constant voltage and current in a circuit. With the development of aircraft power electronics technology, the 540 power supply system has emerged. Today's DC power supplies have a wide input voltage range of 400V-700V, and have small input and output ripples. At the same time, most existing DC power supplies use clamping diodes, and the output ripple current is higher than the single-channel current, and the output voltage is not very stable. Therefore, a DC conversion power supply based on a three-phase interleaved Buck topology circuit is proposed. Summary of the invention

[0003] The purpose of the present invention is to provide a DC conversion power supply based on a three-phase interleaved Buck topology circuit to solve the problems of wide input voltage range, higher output ripple current than single-channel current, and unstable output voltage proposed in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A DC conversion power supply based on a three-phase interleaved Buck topology circuit comprises an input line, a Buck circuit, an output line and a control unit, wherein the input end of the Buck circuit is connected to the input line, the output end of the Buck circuit is connected to the output line, and the Buck circuit comprises a capacitor C1 connected to the input line, a capacitor C2 connected to the output line, and a three-phase half bridge connected between the capacitor C1 and the capacitor C2; the Buck circuit and the control unit form a dual closed-loop control system, which is a voltage and current dual closed-loop control system, and the dual closed-loop control system comprises a voltage regulator, a current regulator and a PWM modulator.

[0005] Furthermore, the three-phase half bridge has six MOS tubes Q1-Q6, and the output end of the three-phase half bridge is connected to three inductors, and the three inductors include inductor L1, inductor L2 and inductor L3.

[0006] Furthermore, the voltage regulator is used to regulate the voltage signal of the voltage loop for output capacitor voltage feedback.

[0007] Furthermore, the current regulator is used to regulate the current signal for the current loop of the inductor current feedback; the output end of the PWM modulator is provided with a signal for comparing the error signal of the current loop with the carrier to generate a KPWM signal.

[0008] The beneficial effects of the present invention are as follows: the present invention sets a three-way MOS tube half bridge, which can reduce the input and output ripple of the DC power supply, improve the conversion efficiency and power density, and realize the conversion of a wide range of input voltage into a stable 270V DC power, which can directly power onboard electrical equipment or be converted into other DC power through secondary conversion, meeting the requirements of high power density, high conversion efficiency and modular power supply structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of a DC power supply of the present invention; Figure 2 It is a principle block diagram of the DC power supply digital control system of the present invention; Figure 3 1 is a circuit diagram of a DC power supply of the present invention.

[0010] In the figure: 1 Inductor No. 1, 2 Inductor No. 2, 3 Inductor No. 3, 4 Three-phase half bridge, 41 MOS tube. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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.

[0012] See also Figure 1-3 , which provides a technical solution for the present invention, a DC conversion power supply based on a three-phase interleaved Buck topology circuit, including an input line, a Buck circuit, an output line and a control unit, the input end of the Buck circuit is connected to the input line, the output end of the Buck circuit is connected to the output line, and the Buck circuit includes a capacitor C1 connected to the input line, a capacitor C2 connected to the output line, and a three-phase half bridge 4 connected between the capacitor C1 and the capacitor C2; the capacitor C1 and the capacitor C2 are used as filter capacitors; the input voltage of the input line is 200-700V, and the output voltage of the output line is 270V; further, the input voltage of the input line is 540V.

[0013] In this embodiment, the three-phase half bridge 4 mentioned has six MOS tubes 41 Q1-Q6, that is, six groups of MOS tubes 41 Q1, Q2, Q3, Q4, Q5 and Q6. The output end of the three-phase half bridge 4 is connected to three inductors, and the three inductors include inductor L1, inductor L2 and inductor L3. Inductor L1 is inductor No. 1, inductor L2 is inductor No. 2, inductor L3 is inductor No. 3, and inductor L1, inductor L2 and inductor L3 are used as filter inductors; wherein, the three-phase half bridge 4 mentioned refers to a circuit of six MOS tubes to realize vector control and square wave control in the circuit.

[0014] In this embodiment, the Buck circuit and the control unit mentioned above form a dual closed-loop control system, which is a voltage and current dual closed-loop control system, and the dual closed-loop control system includes a voltage regulator, a current regulator and a PWM modulator; the voltage regulator is used to adjust the voltage signal for the voltage loop of the output capacitor voltage feedback; the current regulator is used to adjust the current signal for the current loop of the inductor current feedback; the output end of the PWM modulator is provided with a signal for comparing the error signal of the current loop with the carrier to generate a KPWM signal; wherein, the transfer function of the filter link of the current loop has a first transfer function and a second transfer function, the first transfer function mentioned=I / sL, the second transfer function mentioned=(I / sC+Rs) / R; in order to achieve a better current sharing effect on the three paths, a dual closed-loop control is adopted, the voltage loop stabilizes the output voltage, the current loop speeds up the response speed, and ensures the current balance of each path; the dual closed-loop control system is an interlaced Buck master control system and an interlaced Buck slave control system.

[0015] The 540V to 270V DC power supply based on three-phase interleaved Buck can be physically designed according to the rated output power of 6000W, with a physical efficiency of 98.5% and a power density of up to 350W / in³. Among them, the three-way MOS tube 41 three-phase half-bridge can greatly reduce the input and output ripple of the DC power supply, greatly improve the conversion efficiency and power density, and the output ripple current is less than 40% of the single-way current.

[0016] In summary: the 540V to 270V DC power supply based on three-phase interleaved Buck uses MOS tube 41 to replace the clamping diode in the existing DC power supply, solves the power supply problem of other electrical equipment in the aircraft with a wide voltage input range of the 540V power supply system, meets the requirements of high power density, high conversion efficiency and modular power supply design, and can provide a step-down power supply solution for the aircraft's 540V high-voltage power supply system.

[0017] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0018] The above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be understood that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or integrated; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components; among them, there are many ways of detachable installation, for example, it can be through the way of plug-in and snap-fit, for example, through the way of bolt connection, etc.

[0019] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A DC conversion power supply based on a three-phase interleaved Buck topology circuit, characterized in that: The invention comprises an input line, a Buck circuit, an output line and a control unit, wherein the input end of the Buck circuit is connected to the input line, the output end of the Buck circuit is connected to the output line, and the Buck circuit comprises a capacitor C1 connected to the input line, a capacitor C2 connected to the output line, and a three-phase half bridge connected between the capacitor C1 and the capacitor C2; the Buck circuit and the control unit form a double closed-loop control system, which is a voltage and current double closed-loop control system, and the double closed-loop control system comprises a voltage regulator, a current regulator and a PWM modulator.

2. A DC conversion power supply based on a three-phase interleaved Buck topology circuit according to claim 1, characterized in that: The three-phase half bridge has six MOS tubes Q1-Q6. The output end of the three-phase half bridge is connected to three inductors, and the three inductors include an inductor L1, an inductor L2 and an inductor L3.

3. The DC conversion power supply based on the three-phase interleaved Buck topology circuit according to claim 1 is characterized in that: The voltage regulator is used to regulate a voltage signal for a voltage loop of output capacitor voltage feedback.

4. The DC conversion power supply based on the three-phase interleaved Buck topology circuit according to claim 1, characterized in that: The current regulator is used to adjust the current signal for the current loop of the inductor current feedback; the output end of the PWM modulator is provided with a signal for comparing the error signal of the current loop with the carrier to generate a KPWM signal.

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