The Key Technology And Application Of Multifunctional Dynamic Voltage Restorer Between Feeders

With the increase in power load and sensitive load,the importance of grid voltage stability highlight gradually.Dynamic voltage restorer(DVR)has been widely studied and applied for its good governance on voltage fluctuation as a voltage type power quality control device.However,usage of single function of it is low and reduce the value of the device.So a multi-function interline dynamic voltage restorer(IDVR)topology is proposed based on extended functions and application areas thinking,which not only can suppress system voltage fluctuation but to limit the inrush current caused by the transient short circuit.Thus greatly improves the value and prospects of the type device.This paper analyzes the working mechanism and proposes a new control strategy of IDVR.Verify the theoretical analysis of this article through simulation experiments finally.Change the strategies of IDVR and transform it to run at a voltage compensation and filtering characteristics state combined with the actual application needs and operating conditions of a tree branch line different loads of feeders.Both converters transfer energy through the binding DC side.The filter circuit maintains a stable DC voltage with the combination of DC energy storage circuit at the same time removing the harmonic of the load so as to suppress voltage fluctuations on the other side of sensitive load.There are two modes of the proposed topology,one is working in the filtering and voltage compensation state and the other is limiting transient overcurrent of fault phase when a fault occurs by branch restrictions to improve equipment utilization.There exists switching problem on transition of different work states and the same with current limiting and relay protection to remove fault problem.This article has given a detailed analysis and simulation result shown the effectiveness of the topology.The hanging operation of the device is intended for the whole network finally.To fully intuitive understand the interplay between the overall feeder network and the multifunction IDVR,it is choosed to analysis the results in network flow.Select feasibility analysis of voltage compensation and limiting effects.The topology is involved in the trend of the distribution while compensating voltage and has changed the power output of the root by causing changes in the line loss,so as do the limiting state.Thus by the trend analysis of the data,it can visually reflect the interaction of the device and network so that to give better designed parameters.It gives the flow calculation results with the device added before and after and analyzes the effect of current limiting.The topology has a certain reliability and portability in the whole.