Three-phase imbalance adjustment control method, three-phase imbalance adjustment control device and three-phase imbalance adjustment system

Abstract

The invention relates to a three-phase imbalance adjustment control method, a three-phase imbalance adjustment control device and a three-phase imbalance adjustment system. The actual value of three-phase imbalance is obtained according to the current of the maximum current phase and the current of the minimum current phase in currents of three phases collected, and is sent to an outer voltage loop. Then, the difference between the actual value of three-phase imbalance and a given value of three-phase imbalance is calculated. Through voltage and current closed-loop control and positive / negative-sequence dq / abc coordinate transformation, total modulating wave for making active power compensation from the maximum current phase to the minimum current phase is generated, and a control signal for adjusting the active power is generated after modulation. According to the invention, the electric energy of the three phases is redistributed according to the load demand, electric energy can be switched fast between unbalanced lines, and three-phase imbalance at the output side of a power distribution transformer can be adjusted quickly and smoothly. Moreover, the loss of power distribution lines can be reduced effectively, the output power of power distribution transformers and the safety operation ability of the power distribution system are improved, and the quality of power supply to users is improved.

Description

technical field [0001] The invention belongs to the technical field of power system distribution network automation, and in particular relates to a three-phase unbalance adjustment control method, a device and a three-phase unbalance adjustment system. Background technique [0002] In the power system, the inconsistency of the three-phase current or voltage amplitude, and the amplitude difference exceeds the specified range, is called three-phase unbalance. The low-voltage distribution network is mainly a voltage network that is stepped down by a 10KV / 0.4KV distribution transformer. Since the distribution network is a mixed power grid for three-phase and single-phase users, the voltage distribution network often uses a three-phase four-wire system. powered by. The output side of the distribution transformer is connected to the low-voltage AC busbar of the three-phase low-voltage distribution network, and the low-voltage AC busbar is distributed into multiple low-voltage out...

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is to provide a three-phase unbalance adjustment control method, device and three-phase unbalance adjustment system, which are used to solve the three-phase unbalance problem of the distribution transformer output of the low-voltage distribution network, and the three-phase unbalance in the prior art The problem of low adjustment accuracy in the unbalanced adjustment method

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