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

Abstract

The invention discloses a three-phase load balancing control system for a low-voltage power distribution network. The power load of a user side is divided into a low-power load part directly connected into the power distribution network and a high-power load part connected into the power distribution network through a phase commutation device. The total power load of each user side and a multi-preset-cycle power average value of a to-be-connected phase commutation device are acquired, the phase with the low total phase power load of the low-voltage power distribution network or the phase commutation device needing trial phase switching on the phase with the low total phase power load is determined through calculation, the phase of the phase commutation device tries to be switched, the to-be-connected phase commutation device tries to be connected into the phase with the low total phase power load, if the loads of the three phases meet the balance requirement, the phase of the phase commutation device is switched to a target phase, and the to-be-connected phase commutation device is connected into the phase with the low total phase power load. The condition that the loads of the three phases are unbalanced is not likely to be caused by connection of the phase commutation devices, a little number of phase commutation devices need phase switching, harmonic interference on the power distribution network by phase switching can be reduced, and the load devices of the user sides can keep operating stably.

Description

technical field [0001] The invention belongs to the technical field of power distribution of low-voltage distribution network, and in particular relates to a three-phase load balancing control system of low-voltage distribution network. 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 network. The three-phase current of the netw...

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Problems solved by technology

The method disclosed in the above-mentioned Chinese patent enables the low-voltage distribution network to maintain a three-phase load balance operation by switching the phases of the user terminal connected to the low-voltage distribution network in real time, but it only performs balancing processing after the user terminal is connected to the distribution network, which requires The number of user terminals that are switched separately is large; the access phase of the phase commutation device at the user terminal is switched from one phase to another, which on the one hand generates harmonic interference to the low-voltage distribution network, and on the other hand affects the configured sensitivity Stable operation of load devices with moving parts, such as washing machines, air conditioners and other motors with built-in inductive moving parts, when the connected phase is switched from one phase to another, due to a sudden phase change, the inductive moving parts will change phases violently Vibration, noise, or even damage to magnetic drive components

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