Research On Detection And Regulation Of Power Quality Problems In DC Distribution Network

With the development and utilization of distributed power sources and the emergence of new power consumption methods,a large number of DC loads are connected to the grid.Because of its advantages in power supply capacity,flexibility and economy,the DC distribution network has received extensive attention from scholars at home and abroad.The use of highly intelligent precision equipment has increasingly stringent requirements on power quality.But the DC system has differences in the topology,power flow form,operating characteristics with traditional AC usage method,so the formation mechanism,manifestation and the resulting consequences of DC power quality problems have new characteristics.Analysis and solving these issues are conducive to promoting the popularization and development of DC distribution networks.This article focuses on the power quality of the DC distribution network and research on its detection and governance.First,the research status of the domestic and foreign research on the power quality of DC distribution network is described.Since the power quality system of the DC system has not yet been formed,comprehensively refer to the research results on the voltage level division,topology structure,and device characteristics of the DC distribution network around the world,and use the power quality indicators of the AC system to analyze the common types of disturbances in the DC distribution network.The above is to provide a reference basis for the development of DC power quality assessment standards and index limits.Secondly,for the detection of power quality of DC distribution network,improves the detect method based on Matching Pursuit algorithm.The genetic algorithm is used to optimize the MP algorithm,and a coarse search is performed before a fine search.This approach reduces the complexity of the need to traverse the complete dictionary for the signal and do a lot of inner product operations in the process of finding the best matching atom.It effectively reduces the amount of calculation,and improves the efficiency while ensuring the detection accuracy of the algorithm.It can decompose and extract the characteristic information of various disturbances from the DC bus signal,determine the disturbance type,and complete the detection of power quality problems.An example of low-voltage DC distribution network verifies the feasibility and effectiveness of the proposed algorithm.Finally,in view of the power quality problem that is widespread in the DC distribution network,based on the study of the AC dynamic voltage restorer,the DC dynamic voltage restorer is used to manage the bus voltage sag and swell phenomenon.Improve and stabilize the power supply and consumption quality of the DC distribution network.The device is simulated and modeled on the MATLAB/Simulink software platform.The results show that the device can realize the compensation function of the distribution bus or load voltage sag and the smoothing effect of the voltage swell.Ensure the quality of load power and improve the safety of the system.The correctness of the proposed topology and the effectiveness of the control system are verified.