A Novel Electro Magnetic Interference (EMI) Filter to mitigate Electro Magnetic Interference in a Zero Voltage Transition (ZVT) Technique based Boost Power Factor Correction Converter P. Ram Mohan 1 , M.Vijaya Kumar 2 , O.V.Raghava Reddy 3 1 Asst. Prof., G.P.R.Engg. College, Kurnool, Andhra Pradesh, India 2 Associate Professor, JNTU College of Engg., Anantapur, Andhra Pradesh, India 3 Scientist, ISRO Satellite Center, Bangalore, India rammohan_cdp@yahoo.co.in Abstract- In this paper, the issues of Electro Magnetic Interference (EMI) and its suppression in a Power Electronic System is presented. Different noises especially common mode noise and differential mode noise are analysed. A Boost PFC circuit employing ZVT technique is analysed and then an EMI filter is designed in the input side of PFC converter to protect the converter from the line side Electro magnetic Interferences. The prototype of proposed EMI filter is built for the PFC Converter. I. INTRODUCTION The demand for power, which has increased tremendously over the last few decades, has forced the power engineers to establish reliable network in order to supply “quality” power to the consumer. Over the years lot of research has been carried out for the supply of quality power to the consumers. This research got a tremendous boost with the strides made in the miniaturization of the electrical industry.[1,2]. The power electronic devices are very versatile devices capable of delivering power as high as 10KW; also these devices are capable of working at frequencies in the range of hundreds of KHZ & at the same time the control being only at the gate terminal of the devices, which makes these devices easily controllable [3,4]. Because of these high frequencies EMI occurs. Generally EMI problems arise due to the sudden changes in voltage (dv/dt) or current (di/dt) levels in a waveform. In diode rectifier, the line current can be pulse of short duration and the diode recovery current pulse can generate transient voltage spikes in the line inductance. A conductor carrying dv/dt wave acts like an antenna and sensitive signal circuit and appear as noise. The EMI problems create communication line interference with sensitive signal electronic circuits [5-8]. II. THE PROBLEM OF EMI Widespread use of electric and electronic systems for household, industrial, communications and other applications makes it necessary for circuits to operate on close proximity of each other. Often these circuits affect performance of other nearby circuits adversely via inadvertent coupling of their signals through near and far region, propagating EM fields. This interference is thus called Electro Magnetic Interference (EMI) is emerging to be a major problem for designers. In addition, the use of integrated circuits has reduced the size of electronic equipment; more circuits are being put in less space, thereby increasing the problem of interference. Equipment designers need to make sure that their equipment will work in the “real world,” with other equipment nearby. This implies that the equipment performance should not be affected by external noise sources and equipment should not itself be a source of noise. Avoidance of EMI is a major design objective, besides the principal objective of achieving intended circuit function. Electromagnetic Compatibility (EMC) is the ability of Electronic Equipment to be able to operate properly despite interference from its Intended Electromagnetic Environment and equally important, not to be a source of undue interference to other equipment intended to working the same environment. EMI was recognized as a problem almost immediately after commercial use of electrical power became common at the beginning of the 20th century. The problem acquired significant dimensions around 1920 when regular radio transmission worldwide became widespread. The first systematic studies on EMI took place in both the United States and Europe in the 1930s. It was soon recognized that the major sources of EMI were radio transmitters, electrical machinery both in the home and in industry, electrical power lines and automobile ignition. The International Special Committee on Radio Interference (CISPR) held its first meeting in 1934 in Europe. The last 20 years have seen a virtual explosion in the use of electrically operated devices such as computers, television sets, VCRs, communication equipment such as FAX machines, modems and high speed radio links for digital data transmission. Hand-in-hand with this growth, is the very severe pressure on the electromagnetic spectrum, as the available bands are now crammed very tightly with users of all descriptions. The rapid growth in the use of personal 1-4244-0726-5/06/$20.00 '2006 IEEE 1408