Journal of Electrical Engineering www.jee.ro 1 REGULATION OF OUTPUT VOLTAGE IN BOOST POWER FACTOR CORRECTION CONVERTER WITH ELECTRO MAGNETIC INTERFERENCE FILTER P. RAM MOHAN Assistant Professor, G. Pulla Reddy Engg. College, Kurnool, Andhra Pradesh, India rammohan_cdp@yahoo.co.in M. VIJAYA KUMAR Professor, JNTU College of Engineering, Anantapur, Andhra Pradesh, India O.V. RAGHAVA REDDY Scientist, ISRO Satellite Center, Bangalore, Karnataka, India Abstract: This paper deals with the closed loop control of a Boost Power Factor Correction (PFC) Converter with Electro Magnetic Interference (EMI) Filter to regulate the output voltage for the source side and load side disturbances. Circuit model for closed loop controlled boost power factor correction converter is developed. A controller is used to regulate the output voltage. The converter is simulated for resistive load. Using the proposed control scheme, the improved power factor at the line side of the converter and regulated output voltage on the load side of the converter are obtained. Key words: Power Factor Correction, Electro Magnetic Interference, Boost Converter, regulation, disturbance 1. Introduction Various types of single-phase PFC converter circuits have been developed and used to improve the ac current waveform [1-4]. The PFC converter is constructed by use of a boost chopper circuit with a switching device in the dc side of the diode bridge rectifier circuit. A sinusoidal current waveform in phase with the ac line voltage and the constant dc voltage can be obtained from PFC converter. Reference [5] discusses the design of Power Factor Correction Boost Converter using genetic algorithms. Digital Power Factor Correction Control Strategy optimized for DSP is given by [6]. Soft switched high power factor boost converter with IGBTs is given by [7]. Electro Magnetic Interference is related with the disturbance caused by electro magnetic waves in the operation of any electronic circuit. Because of rapid change in voltages and currents within a switching converter, power electronic equipment is a source of electro magnetic interference. So, Electro Magnetic Interference Filter (EMI Filter) has to be used at the input of PFC converter to minimize the interference [8-10]. The modeling and design of boost PFC converter with low common mode EMI is presented in [11]. The detail about mixed mode EMI noise is given by [12]. Modeling and characterization of PFC converter in the medium and high frequency ranges for predicting the conducted EMI is given by [13]. In this paper, the simulation work on closed loop control circuit for the Boost PFC Converter with EMI Filter is done to regulate the output voltage for source side and load side disturbances. The simulation results are presented in this paper. 2. Analysis of Boost Converter Fig.1 shows the boost converter where the output voltage is greater than the input voltage. Boost converter is also called as step-up converter. A large inductor in series with the source voltage is essential. When the switch is on, the input current flows through the inductor and switch and the inductor stores the energy during this period. When the switch is off, the inductor current cannot die down instantaneously; this current is forced to flow through the diode and the load during this off period. As the current tends to decrease, polarity of the emf induced in L b is reversed. As a result, voltage across the load is the sum of supply voltage and inductor voltage and it is greater than the supply voltage. R S d load V g L C 0 V V D 0 Fig.1. Boost Converter The voltage impressed across the inductor during on-period is V d . During this period, the current rises linearly from a minimum level I 1 to a maximum level I 2 . Therefore the voltage across inductor is, 1