Research On The Low Voltage Side Harmonic Analysis And Control Strategy Of Industrial Power Supply System

With the development of industry,the customer on product quality requirements more and more high,inverter,soft starter,UPS,rectifiers,inverters and other nonlinear load equipment in the use of a large number of production line,harmonic components accounted for the ratio of power system is more and more,to the power grid caused harmonic pollution and increase the reactive power,seriously affect the quality of power supply and reduce operating efficiency of electric equipment,affecting normal work of electric equipment and communication equipment,so bring effective harmonic harm extremely urgent.In this paper,we have carried out the waveform monitoring and data analysis for the hot rolling mill.The characteristics of the hot rolling load,because of the operating characteristics of the hot rolling production,the instantaneous impact load,and the load state,the transformer power factor is less than 0.6,the transformer reactive power loss is relatively large,the power supply system stability is weak.Secondly,the definition,damage and control methods of harmonic are studied.The structure,control principle and control strategy of passive filter,active power filter and hybrid filter are analyzed in detail,which provides a theoretical basis for improving the low voltage power supply side of the hot rolling mill.In this paper,the control strategy of harmonic control in low voltage power supply system is studied,and the harmonic control scheme is designed.The method of passive filter and active power filter is adopted to solve the problem of low power factor,line and transformer loss.Active power filter(APF)is the use of switching elements,through the DSP digital signal processing and PWM pulse width modulation technology,according to a harmonic component of the detected,resulting in an equal amplitude and opposite phase current,by injecting power supply system in the position of the harmonic sources,to make the power total harmonic zero to dynamic compensation harmonic current.It also can suppress flicker,compensate reactive power,control the whole digital realization,DSP TMS320F2812 data storage and processing chip + EP1C6240C8 sampling and separation chip FPGA.In the design of control circuit,the advantages of FPGA and DSP are fully considered.Finally,through the actual effect,the data is collected and analyzed,so that the harmonic current,the harmonic voltage and the total harmonic distortion rate of the power supply equipment meet the relevant provisions of the national standards.Achieve power factor improvement.