Single-phase electricity-to-three-phase electricity conversion power supply device and control method thereof

Abstract

The invention discloses a single-phase electricity-to-three-phase electricity conversion power supply device and a control method thereof, and belongs to the technical field of power grid power supplyand distribution. A power transmission line is connected to a terminal P at the input end of an isolation transformer, and a terminal Q at the input end of the isolation transformer is grounded or connected to a return line; a terminal M and a terminal N at the output end of the isolation transformer are respectively connected with a terminal R and a terminal S at the input end of a power converter in sequence; a terminal J1 and a terminal K3 at the output end of the power converter are jointly connected to the phase A of the triangular winding of a three-phase Dyn transformer, a terminal K1and a terminal J2 at the output end of the power converter are jointly connected to the C phase of the triangular winding of the three-phase Dyn transformer, and a terminal K2 and a terminal J3 at theoutput end of the power converter are jointly connected to the phase B of the triangular winding of the three-phase Dyn transformer; and a terminal a, a terminal b and a terminal c at the output endof the star-shaped winding of the three-phase Dyn transformer T are connected with a low-voltage power distribution network with a grounded neutral point.

Description

technical field [0001] The invention relates to the technical field of electric power grid power supply and distribution. Background technique [0002] Users in the field of low-voltage power distribution in my country generally use single-phase power supply. When users need to use three-phase power, they need to re-erect power lines, which is very troublesome and takes a long time; Two-phase transmission lines, three-phase Dyn transformers are connected to users, which is more economical and does not take up space, but some users need three-phase power. In particular, the user needs to use the three-phase power supply for a short period of time due to special reasons, and the time for erecting a new three-phase line is not allowed. If the power quality of the grid allows, the three-phase power supply can be provided relatively easily, which will have a greater impact economic and social value. [0003] In the power distribution system, due to long-term mechanical force, el...

AI Technical Summary

Problems solved by technology

The common reasons for disconnection in the distribution network are: (1) The wire joints are loose, especially when the copper and aluminum wires are connected, the contact surface will be galvanically corroded, which will increase the contact resistance and heat generation. The resistance is further increased, and such a vicious circle will inevitably blow the copper-aluminum spliced ​​joint; (2) When installing a fuse, one phase of the fuse is blown due to a certain phase being injured or the capacity of the three phases is inconsistent; (3) Switching or starting A certain phase contact of the equipment is burned, loose, or poor contact; (4) A certain phase of the motor winding is disconnected or the connector is loose, etc.

[0004] In the rural power grid, the users are scattered geographically, and some homes may have small workshops or small workshops, and the power system is sometimes set up with three-phase lines, but due to the low poles, one phase of the wire may be broken in bad weather conditions Or two-phase line, in the case of strong wind or rain, it is very dangerous to carry out emergency repairs

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