Research And Design Of Three Phase Unbalance Monitoring Device For Low Voltage Distribution Network

At present, the low voltage distribution network in China is mainly supplied by the transformer by means of three-phase four wire system. In the low voltage power distribution network in China, the problem of three-phase unbalance always exists. The appearance of three-phase unbalance is due to the uneven distribution of the electric load in each phase. In addition, China’s distribution network has been difficult to achieve more advanced automation, this problem is difficult to solve for a long time. If the power grid is in a long term operation under three-phase unbalanced conditions, it can bring serious harm to both power supply and power supply. So it is in urgent need of a three-phase unbalanced monitoring device, real-time monitoring of the imbalance of the status, so as to find the corresponding improvement measures. The main research contents of this paper are the following:(1) After studying the mainstream algorithm of various power quality monitoring, the mixed radix FFT algorithm is finally determined;(2) The overall design of three phase unbalance monitoring device is designed, and the various core hardware modules are analyzed, and the programming idea about software is determined;(3) Three phase unbalance monitoring device is debugged and trailed under the condition of laboratory to verify the accuracy and reliability of the device; Furthermore, the monitoring device is installed in the low voltage distribution network. Analysis results show that the three phase unbalance monitoring device can monitor the three phase unbalance in power distribution network.