Novel sampling algorithm for DSP controlled 2 kW PFC converter

has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. iii Mather, Barry A. (Ph.D., Electrical Engineering) Digital Control Techniques for Single-Phase Power Factor Correction Rectifiers Thesis directed by Professor Dragan Maksimović Tightening governmental regulations and industry standards for input current harmonics and input power factor correction (PFC) of common electronic devices such as servers, computers and televisions continues to increase the need for high-performance, low-cost power factor correction controllers. In response to this need, digital non-linear carrier (DNLC) PFC control has been developed and is presented in this thesis. DNLC PFC control offers many unique advantages over existing PFC control techniques in terms of design simplicity, low harmonic current shaping over a wide load range including CCM and DCM operation and a reliable, inexpensive digital implementation based on low-resolution analog-to-digital converters (A/D's) and digital pulse width modulator (DPWM). Implementation of the controller requires no microcontroller or digital signal processor (DSP) programming, and is well suited for a simple, low-cost integrated-circuit realization. DNLC PFC control is derived and analyzed for single-phase universal input PFC boost rectifiers. Further analysis of the operation of digitally controlled PFC rectifiers leads to the development of voltage loop compensator design constraints that avoid limit-cycling of the voltage loop. It is demonstrated that voltage loop limit-cycling is unavoidable when using traditional PFC control techniques under certain output loading conditions. However, it is also shown that voltage loop limit-cycling is avoidable under the same operating conditions when a DNLC PFC controller is implemented. Additionally, a unique output voltage sensing A/D is also developed that improves the PFC voltage loop transient response to load transients when paired with the DNLC PFC controller. Experimental results are shown for a 300W universal input boost PFC rectifier. iv

Proc. PEMC'94, 1994

frequency. The simulation results are verified through MATLAB simulink. Keywords:-Modeling of DC-DC Boost Converter, average current mode control, power factor correction and simulation results. 1 C.Brahmananda Babu is pursing M.Tech in

Twentieth Annual IEEE Applied Power Electronics Conference and Exposition, 2005. APEC 2005.

A single DSP controlled two phase interleaved PFC converter is presented together wlth its digital control design and Implementation. A simple, low cost method of sensing the switch current and implementing the current share control is illustrated. Details of the design are presented to show the simplification of the control Implementation achieved through the use of a DSP. Finally, experimental results are provided to validate the performance of the digital implementation.

IET Power Electronics, 2011

Power factor correction (PFC) pre-regulators are used between the ac line and non-linear load to improve the line current in terms of power factor and total harmonic distortion (THD). In medium-and high-power applications, the interleaved boost PFC converter is the proper solution for this purpose to obtain a pre-regulator with lower size. The operation of the interleaved boost PFC converter provides a reduction of the inductor and electromagnetic interference filter volumes compared with those of the conventional single switch boost PFC converter. However, proper current sharing and current ripple minimisation must be ensured to achieve these benefits. The current sharing between cells of a two-cell interleaved boost PFC converter, which is an important problem in applications is analysed and discussed in this study and the problem is removed by using a digital signal processing (DSP)-based simple practical solution. The proposed technique provides the proper current sharing by sensing only the rectifier output current (total current of cells) without using any external control loop. The simulation and the experimental results are presented to show the validity.

A Microcontroller based power factor correction (PFC) converter is proposed, which is not affected by harmonic distortion in current and voltage wave shapes. This paper describes the design and simulation of a single-phase PFC converter using Atmel's AVR Microcontroller. It involves sensing and measuring the power factor from the load using ADC; implementing faster algorithm to process the data using discrete time filter which requires least amount of memory; and triggering appropriate capacitors in order to compensate the excessive reactive components. A power factor near to unity is thus achieved, which results higher efficiency and low-THD AC output. A provision for measuring the power is also discussed.

IET Power Electronics, 2012

This study presents an average sliding control (ASC) method to be used in power factor correction (PFC) circuits to decrease the total harmonic distortion (THD) of the input current by eliminating the input current harmonics. The ASC algorithm is adapted to TMS320F2812 digital signal processor (DSP) owing to its well-known properties, such as robustness, stability and good regulation in a wide range of operating conditions. The control approach is operated in continuous conduction mode. In this approach, a sinusoidal signal is generated by the DSP and is used as reference in controlling the converter switch to obtain a sinusoidal input current based on zero-crossing points of input voltage. The feed-forward is also used in the control algorithm using maximum value of the input voltage. The implementation of feed-forward improves the converter's performance to obtain a near-unity PFC with a lower input current THD. The converter used in the simulation and experimental studies is a bridgeless converter. The conduction losses of the switches of this converter are lower compared with the similar PFC converters. The experiments performed in the laboratory for different cases of operation verify the theoretical and simulation studies. The experimental results are satisfied by IEC 61000-3-2 current harmonic standard.

IEICE Electronics Express, 2014

A novel digital control algorithm for a single-phase boost power factor correction (PFC) converter with fast dynamic response is presented. Based on the converter circuit structure, the track of the output voltage and the inductor current of next switching cycle is estimated in advance. The self-adjusting voltage control loop is adopted to improve the static and dynamic voltage regulation. Meanwhile, the current control loop is implemented only by the estimated output voltage and inductor current values, which simplifies the control loop and reduces the digital calculation burden. The single-phase boost PFC converter with the proposed digital control algorithm has been implemented via the field programmable gate array (FPGA). Experimental results indicate that the proposed control algorithm can improve the power factor, as well as the dynamic response of boost PFC converter simultaneously. The power factor is optimized more than 0.98, and the recovery time is less than 4 line cycles with small overshoot.

2008

Abstract For low-power AC-DC converters, power factor correction (PFC) can be accomplished simply with certain converters operating in discontinuous conduction mode (DCM). At higher power levels, DCM results in higher losses, so most PFC converters use current feedback to actively track the correct current waveshape. This work presents a way to provide PFC control without the current sensor, by replacing the sensor with a Kalman filter, which is essentially a stochastic observer.

IET Power Electronics, 2019

A comparison of fuzzy self-tuning (FST), sliding mode control (SMC) and conventional proportional-integral (PI) control methods is performed under unbalanced grid conditions using a bridgeless power factor correction (PFC) converter. The bridgeless PFC converter operates the correction of AC line current to obtain a DC output voltage without full bridge rectifier based on these control methods. These control methods generate the duty cycles to provide higher unity power factor and lower total harmonic distortion of input current, even if AC line voltage is distorted. This study focuses on the performance analysis of FST and SMC methods adaptation to the input current for the bridgeless PFC converter and comparing with the conventional PI controller. Although the SMC method is only used in the current control loop, the FST method is used in both current and voltage control loops for eliminating harmonics of input current and regulating of output voltage. The performance of control methods is evaluated with a TMS320F2812 digital signal processor. The simulation and experimental results are compatible with the limits for harmonic current emissions, IEC 61000-3-2 and show that the FST and SMC are better than the conventional PI control method and FST is superior to the SMC.