Research On Harmonic Suppression Technology Of Hybrid Filter

In recent decades,power electronic devices are more and more widely used in Daqing oilfield distribution network.Due to the gradual use of frequency control devices in the gathering and transportation system,water injection system,mechanical oil production system,UPS uninterrupted power supply,energy saving auxiliary equipment,etc,the increasing of nonlinear load capacity of oil field power grid brings the problem of harmonic pollution.The hybrid filter is a combination of passive filter and active power filter.Based on the analysis of the problem of passive filter,which is easy to cause the problem of detuning,the paper proposes to use the dynamic passive filter of adjustable capacitor groups and adjustable reactors in harmonic suppression of Daqing oil field,and then verifies the effective and superiority of the dynamic passive filter with simulation.The paper research deeply in detection methods,control methods and main circuit parameters of active power filter,in the part of detection method contrast two traditional methods:p-q method based on instantaneous reactive power and ip-iq method based on instantaneous reactive power.This paper proposes a ip-iq method with improved low-pass filter.The part of control method analyses and compares with the triangle wave comparison method,instantaneous value comparison method and the space vector method,and makes sure that the space vector method is the best in the APF designed.Finally it verifies that this APF has good dynamic performance and effective.The paper discussed the capacity of the active part of the three common typologies of the hybrid filter.Through analysis and calculation,the capacity of the active part may gets down to 5%of the load capacity.The paper builds the topology structure that adding the fundamental resonance branch,and reduces the active capacity capacity to less than 2%of the load capacity further.Base on the MATLAB/SIMULINK simulated the hybrid filter designed in this paper,aiming at typical harmonic sources,given the device parameters.Finally the simulation results show that the hybrid filter designed in this paper meet the requirements for harmonic control in oil field,when the power is distorting or the load is mutating,it can implement the function of harmonic Suppression,and the results are better than the use of passive filter or the use of active filter alone for harmonic suppression.So the hybrid filter designed in this paper has a promotional value.