Intelligent phase-changing switch system for adjusting three-phase imbalance and method of intelligent phase-changing switch system

Abstract

The invention relates to an intelligent phase-changing switch system for adjusting three-phase imbalance and a method of the intelligent phase-changing switch system. The intelligent phase-changing switch system is characterized in that the system includes main controllers and phase-changing switches, wherein the main controllers are installed on branch line outgoing wires respectively, and the phase-changing switches are installed at the front ends of users. According to the method, load current effective values are collected in real time and are sent to the main controllers actively; the main controllers collect three-phase current values on branch lines at intervals of a fixed period and calculate the degree of three-phase current imbalance; the threshold of the degree of the three-phase imbalance and the threshold of the number of times of line crossing are set; and if the calculated degree of the three-phase imbalance exceeds the threshold, and at the same time, the cumulative number of the times of line crossing exceeds the threshold, a phase-changing adjustment optimization strategy is started. The system and method of the invention are reasonable in design. With the systemand method adopted, the steady three-phase load balance of branch lines and a transformer power supply zone can be achieved to the greatest extent, the degree of the three-phase imbalance can be low,the number of the action of the switches can be minimum, and therefore, the safety of equipment and the reliability of power supply can be improved.

Description

technical field [0001] The invention belongs to the technical field of low-voltage distribution networks, in particular to an intelligent phase-change switch system and method for adjusting three-phase unbalance. Background technique [0002] With the development of the economic level, the power load is increasing day by day, and the random access of a large number of single-phase loads in the low-voltage distribution network leads to serious three-phase unbalance problems. The three-phase imbalance in the low-voltage distribution network will increase transformer loss and line loss, reduce power quality, cause low voltage at the end of the heavy-duty phase, and cause the equipment to fail to work normally. In severe cases, it may cause single-phase overload tripping and cause power outages in the station area. [0003] At present, the treatment of three-phase unbalance mainly adopts the method of reactive power compensation, and the equipment is mainly composed of thyristor...

AI Technical Summary

Problems solved by technology

Also, shifting the load from a heavily loaded phase to a lightly loaded phase only guarantees instant three-phase balance

In a day, the current value of the load changes, and the change rules of different loads are different, which may cause the commutation switch to operate multiple times in a day to ensure the real-time three-phase balance, which not only increases the workload of the processor, but also causes The global switch operates multiple times, which increases the loss of the switch

Images