Research On Voltage Sag Control Of Sensitive Equipment Based On Dynamic Voltage Restorer

Since its introduction,the inverter has been applied to industrial production due to its excellent speed regulation capacity and significant energy saving effect.However,the inverter is a typical sensitive device that is temporarily reduced to voltage.When the voltage of the power grid is temporarily reduced,the inverter may check out due to the effect of protecting and controlling,interrupting the entire production process,causing huge economic losses.Solving the temporary reduction of the frequency frequency can be achieved by installing the power quality control equipment.At present,the dynamic voltage restorer DVR is one of the ideal devices to solve the temporary drop of voltage.Based on the DVR performance indicators,this article mainly studies the three aspects of the DVR voltage detection method,control strategy and control method.For voltage drop detection,based on the DQ transformation detection of instantaneous powerless theory,this article studies a improved single-phase detection method to construct a virtual three-phase voltage with the guidance method,and use the obtained voltage component to use the mathematical form filtering of the mathematical form filtering.Eliminate the harmonic interference in the grid.In order to cooperate with a single-phase voltage drop detection method,the research of controlling strategies based on the minimum energy compensation method,and proposed that the DVR is limited by the scope of compensation,which cannot be compensated to the load.Optimized compensation method with the minimum modulus before the fault.On the basis of analyzing the poor stability of the feed control and the poor real-time feedback control,a composite control mode combined with the combination of feedback control and feedback control method is finally selected through theory.In response to the traditional PID controller’s problem that cannot be regulated without static differences,a proportional resonance controller was proposed and analyzed performance,and the control method was finally determined.