High Power Factor Power Supply

With the rapid increase of industry and domestic consumption of electric power, power quality began to attract more and more attention. One of the basic rule of power quality is the stability of voltage. It is closely linked to the condition of reactive power. High power factor stabilized voltage supply is a kind of high performance alternating current power supply which can not only steady the output voltage but also enhance the input power factor.Firstly,the paper introduces the concept of power quality and reactive power,traditional alternating current stabilized voltage supply's forms and their characteristic and shortage.Secondly, the paper introduces a new kind of high power factor stabilized voltage supply.At last, the key technique of high power factor stabilized voltage supply is detailedly analyzed.Traditional AC stabilized voltage supply is basically belong to dissipation ofenergy.It's theory is using nonlinear device such as voltage regulator tube or ferroresonance steady voltage transformer assisted with necessary circuit to realize the autoregulation of output voltage. It's ciruit is mature and theory is consummate.But thiskind of supply has some idiopathic shortage.For example,supply using magnetismsaturation has the following shortage:size is big,weight is heavy;cost ishigh,efficiency is low,self-consuming is high;high wave distortion;steady performanceis normal,hard to reach l%.With the rapid progress of power electronic devices andpower transform technology and control theory and micro processing technology,anew kind of technology is born for stabilized voltage supply.It's switching powersupply.It's theory is via controling the swithing divice's lead on and shut off time tosteady the output voltage.Compared with traditional stabilized voltage supply,it's sizeis small and efficiency is high and it's performance is stable.High frequency is it'sdeveloping trend.The swithing frequency will be enhanced from 20kHz to100-500kHz or much higher.Because of it's high frequency,smaller size transformer isused instead of big power-frequency transformer. So the swithing supply's size is small and it's weight is light.It has good dynamic characteristic and stable performance.It's easy to barrage jamming and forming the foundation for the swithing power's integration and automation.Light-duty,low-noise,multi-function,intelligentize and high dependability are the developing trend of stabilized voltage supply. Stabilized voltage supply adopting switching technology to reduce transformer size and low frequency inductance is a new research direction.lt can predigest controlling circuit,reduce cost,enhance reliability and increase power. High power factor stabilized voltage supply adopts switching technology.It's a kind of compensating supply via modulating the compensating voltage to steady output voltage and enhance input power voltage.lt has characteristic of low wave distortion,small size and light weight,realizing multi-function.The controlling of compensating voltage is the key technology.The paper discusses the controlling of compensating voltage in many aspects.lt realized the control through new DSP technoloty. A lot of simulations for the supply designed in this paper are made by using MATLAB to verify the correctness of the circuit designed. The results of simulations prove that this supply design in this paper is reasonable and simple in structure. It has reached a high level and with the satisfying compensation effect.