Low-voltage distribution network three-phase unbalanced treatment system and method controlled by phase-change switch cluster

Abstract

The invention relates to a low-voltage distribution network three-phase unbalanced treatment system and method controlled by a phase-change switch cluster. The system has the following technical characteristics: the system comprises a current transformer, a main control terminal, main control switches and intelligent phase-change switches; the current transformer is installed on the low voltage side of a transformer and connected to a three-phase power grid, and is used to measure a current signal of the low voltage side of the transformer and a beginning end of a three-phase branch line; themain control terminal is used to monitor the unbalance degree of a three-phase line on the low-voltage side of the distribution transformer, collect three-phase current data at the beginning ends of three-phase branch lines in real time and issue a phase-change instruction to the intelligent phase-change switches; the main control switches are connected with the intelligent phase-change switches,and is used to monitor the unbalance degree of the beginning ends of the three-phase branch lines and perform phase-change control on the intelligent phase-change switches; and the intelligent phase-change switches are connected with loads, and are used to receive the phase-change instructions of the main control terminal or the main control switches to switch phases. The imbalance degree of the low-voltage side of the distribution transformer and the beginning ends of the three-phase branch lines can be effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of low-voltage distribution network, and relates to a low-voltage distribution network three-phase unbalance control system and method, in particular to a low-voltage distribution network three-phase unbalance control system and method controlled by a commutation switch cluster. Background technique [0002] Distribution network is an important public infrastructure for national economic and social development. With the acceleration of the country's new urbanization and new rural construction, urban-rural integration, and the rapid development of distributed power supplies and electric vehicles, the low-voltage distribution network has put forward higher requirements for the treatment of three-phase imbalance problems. [0003] The low-voltage distribution network is at the end of the power system, especially in my country's vast rural areas, where there are many and scattered power users, and the operating ...

AI Technical Summary

Problems solved by technology

[0005] At present, the traditional methods of controlling three-phase imbalance mainly include the following: 1) Adjusting the load through manual rerouting, this method has the highest utilization rate, but its labor cost is high, and the user’s power supply needs to be cut off, so it is difficult to adapt to the changing power of the load for a long time ;2) Compensation by SVG static synchronous compensator, SVG static synchronous compensator can compensate the three-phase unbalance, but this method is costly, and can only achieve approximate balance of three-phase current on the low-voltage side of the transformer, not essentially realizing load Balance; 3) Compensation through the APF active filter, the APF active filter can play a certain role in compensating the three-phase unbalance in addition to the function of filtering harmonics, but this method is expensive, and it is not essential load balancing

To sum up, the traditional method is relatively deficient, and the investment is large and the efficiency is low, so it cannot fundamentally solve the three-phase imbalance problem

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