A DC power distribution system

Abstract

The present invention discloses a direct current distribution system. The direct current distribution system includes: a phase-shifting transformer, a rectifier and a four-quadrant operation inverter. The primary side of the phase-shifting transformer is connected to the alternating current grid, and the secondary side of the phase-shifting transformer includes multiple groups of secondary windings, one group of secondary windings is connected to the input end of the four-quadrant operation inverter, and the remaining secondary windings are respectively connected to the input end of a rectifier, and the output end of each rectifier is connected to the direct current bus, and the output end of the four-quadrant operation inverter is connected to the direct current bus. The four-quadrant operation inverter can feed energy back into the grid or absorb energy from the grid according to system needs. The direct current distribution system provided by the present invention only requires one four-quadrant operation inverter to achieve energy feedback, has low implementation cost, high reliability, and has the advantages of no harmonics, no reactive power, and partial power feedback.

Description

Technical Field

[0001] The present invention relates to the field of electrical automation equipment, and in particular to a direct current power distribution system. Background Art

[0002] In the prior art, DC power distribution systems generally use a combination of traditional transformers and rectifiers to distribute power. This solution uses a traditional transformer to transform the AC voltage, and then rectifies the AC voltage into DC through a rectifier. This solution has the problems of large system harmonic content, high reactive power, and low system efficiency. Summary of the invention

[0003] The object of the present invention is to provide a direct current power distribution system having the advantages of no harmonics, no reactive power, partial power feedback, low cost and high reliability.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A DC power distribution system, comprising: a phase-shifting transformer, a rectifier and a four-quadrant operating inverter; wherein:

[0006] The primary side of the phase-shifting transformer is connected to the AC power grid, and the secondary side of the phase-shifting transformer includes multiple groups of secondary windings, one group of which is connected to the input end of the four-quadrant operation inverter, and the remaining secondary windings are respectively connected to the input end of one of the rectifiers, and the output end of each rectifier is connected to a DC bus, and the output end of the four-quadrant operation inverter is connected to the DC bus.

[0007] Optionally, the secondary side of the phase-shifting transformer includes a 0° phase-shifting winding and a ±nθ° phase-shifting winding, wherein n is a natural number and θ is a phase-shifting interval.

[0008] Optionally, the secondary winding connected to the input end of the four-quadrant operating inverter is the 0° phase-shift winding.

[0009] Optionally, the four-quadrant operation inverter is a three-level four-quadrant operation inverter.

[0010] Optionally, the rectifier is a diode rectifier.

[0011] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0012] The DC power distribution system provided by the present invention includes: a phase-shifting transformer, a rectifier and a four-quadrant operation inverter. The primary side of the phase-shifting transformer is connected to the AC power grid, and the secondary side of the phase-shifting transformer includes multiple groups of secondary windings, one of which is connected to the input end of the four-quadrant operation inverter, and the remaining secondary windings are respectively connected to the input end of a rectifier, and the output end of each rectifier is connected to the DC bus, and the output end of the four-quadrant operation inverter is connected to the DC bus. The four-quadrant operation inverter can feed energy back into the power grid or absorb energy from the power grid according to system needs. The AC voltage output by the AC power grid is input into the rectifier for rectification after phase shifting by multiple groups of secondary windings of the phase-shifting transformer, and finally the DC power obtained by rectification is input into the DC bus. The DC power distribution system provided by the present invention only requires one four-quadrant operation inverter to achieve energy feedback, with low implementation cost, high reliability, and the advantages of no harmonics, no reactive power, and partial power feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0014] Figure 1 A topological diagram of a DC power distribution system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] 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.

[0016] The object of the present invention is to provide a direct current power distribution system having the advantages of no harmonics, no reactive power, partial power feedback, low cost and high reliability.

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 The topology diagram of the DC power distribution system provided by the embodiment of the present invention. Figure 1 As shown, the DC power distribution system includes: a phase-shifting transformer 1, a rectifier 2 and a four-quadrant operation inverter 3.

[0019] The primary side of the phase-shifting transformer 1 is connected to the AC power grid 4, and the secondary side of the phase-shifting transformer 1 includes multiple groups of secondary windings, one group of which is connected to the input end of the four-quadrant operation inverter 3, and the remaining secondary windings are respectively connected to the input end of one of the rectifiers 2, and the output end of each rectifier 2 is connected to the DC bus, and the output end of the four-quadrant operation inverter 3 is connected to the DC bus 5.

[0020] The secondary side of the phase-shifting transformer 1 includes a 0° phase-shifting winding and a ±nθ° phase-shifting winding, wherein n is a natural number and θ is a phase-shifting interval. The phase-shifting transformer 1 can perform symmetrical and equal-interval phase shifting on the AC voltage provided by the AC power grid 4. In this embodiment, the phase-shifting interval is 12°. The secondary winding connected to the input end of the four-quadrant inverter 3 is the 0° phase-shifting winding.

[0021] In this embodiment, in order to reduce system cost and harmonic content, the four-quadrant operation inverter 3 is a three-level four-quadrant operation inverter, and the rectifier 2 is a diode rectifier.

[0022] The DC power distribution system provided by the present invention comprises a phase-shifting transformer comprising a plurality of secondary windings, which respectively shift the phase of the AC power grid voltage to generate a plurality of phase-shifted AC voltages with symmetrical phase angles. One of the 0° phase-shifted AC voltages is connected to the three-level four-quadrant inverter, which can feed energy back into the AC power grid or absorb energy from the AC power grid according to system requirements. The remaining plurality of phase-shifted AC voltages are connected to a diode rectifier, which rectifies the AC voltage and inputs it into the DC bus. The DC power distribution system provided by the present invention has the advantages of no harmonics, no reactive power, partial power feedback, low cost, and high reliability.

[0023] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0024] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A DC power distribution system, characterized in that: The DC power distribution system includes: a phase-shifting transformer, a rectifier and a four-quadrant operating inverter; wherein, The primary side of the phase-shifting transformer is connected to the AC power grid, and the secondary side of the phase-shifting transformer includes multiple groups of secondary windings, one group of which is connected to the input end of the four-quadrant operation inverter, and the remaining secondary windings are respectively connected to the input end of one of the rectifiers, and the output end of each rectifier is connected to a DC bus, and the output end of the four-quadrant operation inverter is connected to the DC bus; The secondary side of the phase-shifting transformer includes a 0° phase-shifting winding and a ±nθ ° Phase-shift winding, where n is a natural number and θ is the phase-shift interval; The phase shift interval is 12°; The secondary winding connected to the input end of the four-quadrant operating inverter is the 0° phase-shift winding; The four-quadrant operation inverter is a three-level four-quadrant operation inverter.

2. The DC power distribution system according to claim 1, characterized in that: The rectifier is a diode rectifier.

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