Papers by Keyword: DC-DC

Abstract: The amount of energy generated by an Organic Photovoltaic (OPV) system depends mainly on the following.Such as solar temperatures and irradiations. Depending on the high cost and low efficiency of an organic photovoltaic system, it can be operated at the maximum power point (MPPT) that changes with solar radiation, temperature or load variations. This work presents an improved algorithm for tracking the maximum power point (MPPT) of a OPV system under real climatic conditions. The proposed MPPT is based on the perturbation and observation (P&O) strategy and the variable pitch method which controls the load voltage to ensure optimum operating points of a OPV system.

Abstract: The switched mode dc-dc converters are some of the most widely used power electronics circuits because of high conversion efficiency and flexible output voltage. Many methods have been developed for the control of dc-dc converters. This paper deals with design of controller for dc-dc buck converter using various control techniques. The first two control techniques are based on classical or linear control methods i.e. PI and PID control, while the other two control technique are based on non linear control method i.e. Sliding Mode Control (SMC) and Sliding Mode Proportional Integral Derivative Control (SMC-PID). The output voltage and the inductor current of the applied control techniques are analyzed and compared in transient and steady state region. Also the robustness of the buck converter system is tested for load changes and input voltage variations. Matlab/Simulink is used for the simulations. The detailed simulation results are presented, which compare the performance of the designed controllers for various cases. The results show that the non linear control for DC/DC Buck converter proves to be more robust than linear control especially when dynamic tests are applied.

Abstract: DC-DC converter is a kind of power conversion equipment. Electricity is the direct power for most mechanical industrial equipment currently. However, because of the diversity of mechanical industrial equipment, electricity should be transformed through power conversion equipment. This paper presents a DC-DC boost converter with PWM control method. The hardware and the structure of the core circuit is designed and the boost principle is interpreted. The detail of the configuration circuit around is described as well.

Abstract: This paper designs a single-phase inverter.Battery as a 12V DC input, and output for the 24V,50 HZ standard AC wave. The load is resistive.The power supply adopts the Boost booster and two full-bridge inverter transform. For the control circuit, the preceding Boost converter using tl494 chip control closed-loop feedback and for the inverter part, adopting the 6N137 to finish the optical coupling isolation.Then,through the DSP (TMS320F2812) to complete the output of SPWM modulation.And the modulated SPWM signal can drive chip IR211 conducting the full bridge inverter. Finally, through a low-pass filter output the standard sine AC inverter power.

Abstract: We analyze the reasons why DC-DC switching power supply generates the electromagnetic interference (EMI), and through the FPGA control the digital-to-analog converter (DAC) to output the pulse width modulation (PWM) signal with high precision and slew rate controlled, the slew rates of the voltage and current of external N-channel MOSFET are controlled. So, dv/dt and di/dt can be decreased in the circuit; and the ripple noise and EMI of switching power supply are reduced vastly in this way. Experimental results show that the ripple noise of switching power supply could be reduced by 80% and EMI reduced 15dBμV. The experiment has proved that we can cut down the ripple noise and EMI of switching power supply by lessening the slew rates of the voltage and current of MOSFET switching tube.