Research And Development Of A Dc-type Dynamic Voltage Restorer Based On Hybrid Energy Storage

Due to the intermittency of renewable energy,short-circuit fault and lightning strike,power quality problem is becoming more and more frequent in the modern power system,such as voltage sag,voltage swell,voltage flicker and voltage interruption,etc.Therefore,it is urgent to introduce all kinds of power compensation devices to improve the power quality.This paper takes a hybrid energy storage based DC-type dynamic voltage restorer(DVR)as a research object,aims at studying the basic principle,Circuit modeling,experimental system and application scheme.The main research contents and achievements are as follows:1.A theoretical model of DC-type DVR based on hybrid energy storage is established,including the DC power interaction sub-model,magnetic energy storage(MES)sub-model,battery energy storage(BES)sub-model,MES-BES based digital circuit control sub-model.Based on the above research work,an energy interaction theory model and a simulation analysis model for the proposed DC-type DVR are constructed.2.The electromagnetic simulation and structural optimization of magnetic energy storage magnets are carried out,including the structural design of magnet and finite element simulation,critical current simulation and experimental verification,magnetic inductance calculation and experimental verification.Based on the above research work and results,a practical MES magnet is designed and manufactured for forming a MES-BES based hybrid energy storage system.3.A small-scale DC-type DVR experimental platform is designed,including the platform overall design,magnetic energy storage circuit design and implementation,battery storage circuit design and implementation,system integration and debugging.According to the above research work and achievements,a small-scale DC-type DVR experimental platform is developed in the work.4.Experiment verifications of the DC-type DVR system are implemented,including the construction of experimental environment,test and analysis of cryogenic power electronic circuits,test and analysis of voltage sags suppressions,test and analysis of voltage swell suppressions,test and analysis of voltage ripple suppressions.On the basis of the above research work and achievements,comprehensive performance evaluations of the DC-type DVR system are carried out by integrating with the theoretical simulations and experimental tests.