Reactive Power Optimization In Distribution Networks With Electronic Power Transformer And Distributed Generation

Reactive power optimization can reduce the active power loss and improve the voltage quality, so that the economy and stability of the power distribution network can be promoted. At present, reactive power optimization of distribution network is still by changing the tapping point of On- Load Tap Changer(OLTC). This way to regulate reactive power has such limitation as low accuracy, discontinuity and also poses potential safety risks. Selecting a new means of reactive power regulation which can achieve a more excellent result of reactive power optimization, has great significance to the economic and stability of the distribution network operation.Electronic Power Transformer(EPT) is a new type of transformer equipment, which can not only realize the main functions of the convention transformer, but can also carry on the continuous reactive towards the primary side and the secondary side, has certain advantages as a means of reactive power regulation. Distributed Generation(DG) which has a certain scale in the distribution network is becoming an important source of energy in the power system. Inverter grid-connected DG is similar to EPT in the principle of reactive power regulation, this kind of DG has a low utilization rate and has sufficient capacity to regulate reactive power. It has certain feasibility to select EPT and DG as the reactive power regulation means of distribution network.In this paper, the equivalent model of EPT in reactive power optimization of distribution network has been established, and the advantage of EPT has been verified by simulation calculation; the equivalent model of inverter grid-connected DG has been established in power flow calculation of distribution network, selecting network loss and voltage as the result of the calculation, studying the influence of the power flow calculation of distribution network when accessing DG, the calculation results show that the DG which has suitable selections of access points, active power and the working state can reduce the loss of distribution network, improve the quality of voltage; a selection which can effectively improve the static voltage stability of distribution network of access point of DG has been proposed; finally, using EPT and inverter grid-connected DG as the regulation means of reactive power optimization of distribution network, and obtaining the conclusion of reactive power optimization in distribution networks with EPT and DG by simulation calculation..Simulation results show that reactive power optimization in distribution networks with EPT and DG can achieve good results of r optimization and improve the utilization rate of DG.