Three-phase current unbalance adjusting system for power distribution network

Abstract

The invention discloses a three-phase current unbalance adjusting system for a power distribution network. The three-phase current unbalance adjusting system comprises a control terminal and at least one adjusting switch, wherein a single-phase load accesses a grid through the adjusting switch; and the control terminal calculates the unbalance degree of all phases by acquiring a voltage value of each phase and a current value in the grid, and controls the state of each adjusting switch according to the calculated unbalance degree. The three-phase current unbalance adjusting system for the power distribution network has the advantages that the unbalance of three-phase current can be adjusted in real time; zero-crossing switching can be realized; the system has the characteristics of low loss and high switching speed, and a downstream load is slightly influenced; the system has functions of line electric leakage monitoring, single-phase short-circuit protection, lightning protection and the like; and data which are acquired by the control terminal can be uploaded to a host for power distribution management, and an instruction of the host for the power distribution management is received, so the power distribution network can be digitally managed, and the device is in accordance with a core design idea of a smart grid and plays an important role in energy conservation and consumption reduction.

Description

technical field [0001] The invention relates to a power device, in particular to a three-phase current unbalance adjustment system of a power distribution network. Background technique [0002] Three-phase unbalance has always been one of the main problems in low-voltage distribution networks, especially in rural power grids or urban residential quarters, where most power users use single-phase loads or mixed single-phase and three-phase loads. The power time is uncontrollable, and it is easy to cause the imbalance of the three-phase current of the power grid. [0003] The unbalanced current in the power grid will reduce the power supply efficiency of the line and distribution transformer at the slightest level, or it will cause the phase conductor to burn out, the switch to burn out, and even the distribution transformer to burn out due to the unbalanced load of a certain phase. Therefore, in the relevant regulations, there are strict requirements on the negative current u...

AI Technical Summary

Problems solved by technology

[0002] Three-phase unbalance has always been one of the main problems in low-voltage distribution networks, especially in rural power grids or urban residential quarters, where most power users use single-phase loads or mixed single-phase and three-phase loads. The power time is uncontrollable, which can easily cause the imbalance of the three-phase current of the power grid

However, this kind of device is generally expensive, and is more suitable for centralized compensation, and does not solve the problem of line loss; in addition, there are also disadvantages such as large loss.

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