Research On Three Phase Imbalance Control Of Low Voltage Distribution Network

In operation of low-voltage distribution networks,due to the neglect of reasonable distribution of three-phase loads,uncontrollable capacity expansion of single-phase users,unsynchronized power consumption of single-phase loads,and access to high-power single-phase loads,it is easy to cause Three-phase load of low-voltage networks unbalanced.Unbalanced three-phase load can cause the transformer to be in an unbalanced operating state,with increased losses,aggravating line voltage drops and power losses,and affecting the normal operation of electrical equipment.Therefore,this article discusses the control measures of three-phase load imbalance from reactive power compensation and intelligent commutation,and carries out the following research.Conducted a research on the current situation of three-phase unbalance in low-voltage networks.First,through on-site surveys and grid data collection,etc.,extract typical station samples and load characteristic data to study the current status and causes of its three-phase imbalance.The second is to establish a low-voltage distribution network calculation model based on distribution transformer operation parameters,user load data and low-voltage network structure,to quantitatively evaluate the harm and impact of three-phase load imbalance on low-voltage distribution network operation.Provide a reference for the study of comprehensive governance methods.Carried out the application research of the converter type reactive power compensation device.The effects of various reactive power compensation devices on three-phase load unbalance control are compared,the coordinated control algorithm is studied,and a reactive power compensation device that adjusts the unbalanced current is optimized to provide a comprehensive treatment for three-phase load unbalance and improve power factors.Feasible solution.Through software simulation modeling,analysis and evaluation of the improvement effect of the device on the management of three-phase imbalance.The simulation results show that the coordinated control strategy of the converter access point at the head end of the distribution station area and the group switching capacitors can reduce the frequent switching of the original capacitor reactive compensation and effectively extend the capacitor life.Carried out the application research of intelligent commutation device.Based on the analysis of user load characteristics,research and formulate intelligent load balancingcalculation control strategies to obtain the best phase-by-phase switching scheme.From the aspects of economy,applicability,controllability,etc.,the promotion and transformation are carried out,and the three-phase load is equally divided according to the load change.Through software simulation modeling,the improvement effect of the device on the management of three-phase imbalance is analyzed.The simulation results show that the intelligent commutation device can effectively optimize the three-phase current imbalance,voltage loss,and switching commutation times,etc.,to achieve muti-objective control.On this basis,the technical guiding principles of three-phase load unbalance treatment in low-voltage station areas under different application conditions were proposed,and converter-type compensation devices and intelligent automatic commutation switching devices were applied in the two pilot stations.Phase load imbalance management has achieved remarkable results.