Advantages And Disadvantages Of Dc Converter

It is observed that the power factor is maintained closer to unity when the input voltage is reduced from 230V to 110Vrms. Figure 11 (a) and (b) shows the power factor correction of controller for various load condition such as 20% (60W) and 75% (230W). The power factor for the system is found to be 0.84 for light load condition and 0.99 for full load condition. The THD of input current at full load with predominant third and fifth harmonic components are shown in Figure 12(a) and (b).Third harmonics is found to be 4.8% and fifth harmonic component is 4.9% which are well within IEC 61000-3-2 standard during wide range of load variations. The variation in power factor with load is shown graphically in Figure 13(a). It can be inferred from the graph that improved resettable control operates at high power factor for all load condition whereas the conventional PI control has poor power factor under light load conditions. Figure 13(b) shows the comparison between the efficiency of the converter for varying load conditions with the conventional control method and the resettable integrator control. The converter’s efficiency is maintained at 92% for light load conditions and 96% for fully loaded condition with integrator control technique. Thus the improved resettable integrator controller provides a very simple and reliable solution for power factor correction and

Balanced and distorted currents are produced because the instantaneous output power and the dc-link voltage have high-frequency ripples,

The impact of the proposed sequences has been simulated for 0.4 modulation index with a 0.5 lagging power factor load (power factor angle 60°). The simulation setup consists of the following software: 1) MATLAB/Simulink – used to implement the modulation strategies and switching sequences, and 2) PSIM – used to simulate the T-NPC inverter running with an R-L load and to provide conduction and switching losses of each switch. The inverter switching pulses were generated within Simulink and were fed to PSIM through sim-coupler module which provides a link between PSIM and simulink for the purpose of co-simulation [29].

Zhou, W., Yang, H.X., & Fang, Z.H. (2008) Battery Behaviour Prediction and Battery Working States Analysis of a Hybrid SolarWind Power Generation System, Renewable Energy, 33, (6), pp. 1413–1423.

Switching power converters offer an easy way to regulate both the frequency and magnitude of the voltage and current applied to a motor shown in fig(1). As a result much higher efficiency and performance can be achieved by these motor drives with less generated noises[3].

In the 1970’s the nickel hydrogen battery was introduced as an energy storage subsystem for commercial communication satellites. This led the

The double voltage cell will increase the voltage gain. The clamped-capacitor circuit which is connected to the primary side of the coupled inductor, the voltage stress of the active switch is reduced greatly and the clamped capacitor also transfers the primary leakage energy to the output. At the same time, a diode-capacitor circuit is integrated with the secondary winding for further extending the voltage gain greatly. Furthermore, the energy of secondary leakage inductor can be recycled and the turned off voltage spikes on the main switch are

On the front end of the adjustable frequency drive, a series inductance on the DC side of the semiconductor bridge circuit is called a DC choke. An equivalent AC-side line reactor is comparable to the DC choke, except that the THD of DC choke is less than that of the AC counterpart. A greater reduction of the 5th and 7th harmonics, primarily, is provided by the DC

Common remarks on DC–AC–DC–AC Topologies: Topologies discussed from fig.4-6 have a high-frequency dc-ac inverter at the input side, which converts input dc into high-frequency AC. This high-frequency AC voltage level will be increased using HFT and then converted into dc by using a bridge

Based on the modelling of SRM magnetic circuit, three models of SRM are found in literature: linear model, nonlinear model without mutual inductances, and nonlinear model with mutual inductances. Linear models in [6,7] are designed and simulated readily. On contrast nonlinear models are obtained after a large set of experimental tests to obtain the magnetic characteristics [8-15], or from a finite element method (FEM) analysis [16-18], which takes into consideration the saturation of rotor and stator materials. The nonlinear model is preferable when accurate precision is wanted. The converter used with SRM requires at least one switch per phase due to unidirectional phase current. This is a big advantage when compared to the converters for AC motor drives. Some configurations of converters used in SRM drives are presented in [19-22]. The half-bridge asymmetric converter is the most widely used for SRM drive applications, because of its high

DBR followed by a filter and an isolated zeta converter. The filter is designed to avoid any switching ripple in the DBR and thesupply system. An isolated zeta converter is designed to operate in DCM to act as an inherent power factor corrector. This combinationof DBR and PFC converter is used to feed a BLDC motor drive via a three-phase VSI as shown in Fig. 1. The dc link voltage of the VSI is controlled by varying the duty ratio of the PWM pulses of PFC converter switch. However, VSI is operated in a low frequency switching to achieve an electronic commutation of BLDC motor for reduced switching losses. A single voltage sensor is used at the front-end converter for the control of dc link voltage for speed control of BLDC motor. The proposed drive is designed and its performance is validated on a developed prototype for improved power quality at ac mains for a wide range of speed control and supply voltage variations.

The small single-phase auxiliary motor fed from the 50 or 60 Hz single-phase power and rated 200W is needed by many computers, domestic and industrial applications, office instruments and equipment. One decade ago, there are many applications such as small water pumps ,audio equipment and fans were the exclusive domain of the very low-efficiency shaded pole induction motor. Because of power electronics and the magnets which is cost-effective, cage induction motors can be successfully substituted by PM brushless motors. The amount and size of apparatus and consumption of energy can be reduced by PM brushless motors because they have smaller sizes and higher efficiency.

Abstract—for very high voltage gain of a Photo-Voltaic system, this paper proposed a buck-boost inverter of single stage. DCM (Discontinuous conduction mode) and MPPT (maximum power point tracking) is employed to get one power factor. Minimization of switching losses is employed with only two switches and operated at very high frequency. Easy control capability, optimum size, affordable cost with high voltage gain made the system employable. AC voltage conversion is achieved along with boosting of DC voltage of Photo-Voltaic system of inverter. Obstacle shadow variations also reduced by means of having the possibility of reduced series connected modules; this ability is due to the high voltage gain. Since the proposed design has the two buck boost converter each one operates for only one half cycle and the Discontinuous conduction mode operates at unit power factor. Simulation results assure the proposed idea of the single stage interleaved inverter for high voltage gain applications.

Multilevel inverters have ability to generate low switching frequency high quality output waveforms with several high voltages and high power applications. The general structure of the multilevel converter to synthesize a

The ordinary low power E & I core transformer is used to get required voltage. It is basically step down transformer, which reduce the voltage from mains supply depending upon the output voltage. The rectifier sections convert AC into DC. The rectifier is designed using four 1N 4007 diode. It is a bridge type rectifier, which give full cycle conduction output. The capacitor based filter section smooth the rippled DC and make it as pure DC. The smoothing level is increased by increasing filter capacitor value. The regulator block is designed using 78 XX series.