Three-phase load balancing system for low-voltage power distribution network

Abstract

The invention discloses a three-phase load balancing system for a low-voltage power distribution network. The three-phase load balancing system comprises a main control station and multiple phase commutation devices; the main control station tries to connect the to-be-connected phase commutation devices into the power distribution network, if a phase enabling the load of the power distribution network to be balanced exists, the phase is taken as a target connection phase; otherwise, the to-be-connected phase commutation device tries to be connected into three phases of the power distribution network sequentially, in order to enable the load of the power distribution network to be balanced, the phase commutation devices, not supplying power to load devices with built-in nastic movement parts, of the power distribution network are identified, a trial connection phase selects the phase commutation devices which are identified firstly and then selects the phase commutation devices which are not identified if the phase commutation devices which are identified are not enough to enable the load of the power distribution network to be balanced, and the trial connection phase selecting the least phase commutation devices which are not identified is determined as the target connection phase; and the to-be-connected phase commutation device is controlled to be connected into the target connection phase. The condition that the load of the power distribution network is unbalanced due to connection of the phase commutation devices is not prone to occur, a little number of phase commutation devices need phase switching, and the load devices can keep operating stably.

Description

technical field [0001] The invention relates to a load balancing technology of a low-voltage distribution network, in particular to a three-phase load balancing system of a low-voltage distribution network, and belongs to the technical field of low-voltage power distribution. Background technique [0002] The load of the distribution transformer of the low-voltage distribution network is generally composed of a mixture of three-phase loads and single-phase loads. Residential electricity is all single-phase loads, and the distribution network is relatively complicated, especially when a large number of single-phase loads are connected to the low-voltage distribution network. system, and the load size is different and the power consumption time is different, so the imbalance between the three phases of the low-voltage distribution network is irregular and unpredictable in advance, resulting in the long-term imbalance of the three-phase load of the low-voltage distribution netwo...

AI Technical Summary

Problems solved by technology

The balance system disclosed in the above patent application keeps the three-phase load balance of the low-voltage distribution network by switching the phase difference between the user terminal and the low-voltage distribution network in real time. There are a large number of user terminals that are switched separately; on the one hand, it will cause harmonic interference to the low-voltage distribution network, and on the other hand, it will affect the stable operation of the load device configured with inductive moving parts at the user end, such as washing machines and air conditioners with built-in inductive moving parts. When the motor is connected to the phase switch, the power supply phase changes suddenly, resulting in violent commutation vibration of the perceptual moving parts, resulting in noise and even damage

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