the paper as validation of assertions and proposals . The Basic requirements of battery chargers with switching regulators are small sized and high efficiency. High switching frequency is necessary to achieve a small size. However, the switching loss will increase as the switching frequency is increased. This condition, in turn, decreases the efficiency. To solve this problem, some kinds of soft-switching techniques need to be used to operate under high switching frequency. One simple solution to a soft-switching converter is loaded resonant converters. By adopting these topologies, either voltage or current is zero during switching transition, which largely reduce the switching loss and also increase the reliability for the battery charger. It eliminates both lowland high frequency current ripples on the battery, thus maximizing battery life without penalizing the volume of the charger . The isolated unidirectional LLC resonant converter is known for its outstanding efficiency and high power density. Little information has however been published about the possibility of transferring power in the reverse direction. This paper presents modulation schemes for making the LLC converter bidirectional. High efficiencies are predicted for both directions of power flow, though, as the behavior of the resonant tank is substantially different in the reverse direction, some of the inherent benefits of the conventional LLC converter are lost . In this paper a topology for multi-phase interleaved LLC resonant converter is presented. The proposed solution, based on three LLC modules with transformer primary windings star connection allows to drastically reduce the output current ripple and consequently to minimize the output filter capacitor size. Differently from other multi-phase
semiconductor devices are operated in soft switching mode in multi-resonant converters. But current or voltage stress is high in these converters. Resonant-transition converters are the one which needs an additional cost of adding an auxiliary circuit, which shape the switching waveforms without much increase in the switch stress. A large capacitor is needed in active-clamp converters and a full bridge network is loaded with a inductive load in phase-controlled converters to have zero voltage switching condition. These converters have the drawbacks of poor performance.
The dc-dc converter presented here offers significant advantages over traditional designs. The power stage inverter provides efficient dc-dc conversion at very high frequencies, with few small-valued passive components and low device stresses. The multi-stage resonant gate driver developed here provides high-speed, low-loss driving of the inverter. Due to the small values and energy storage of the passive components in both the power stage and gate driver, the transient response can be very fast compared to conventional designs, and the converter is especially well suited to on-off control.
The distinguishing feature of soft switched converters is that they switch ON and OFF at zerocurrent or zero voltage. In zerocurrentswitching, the switch turns ON from a finite blocking voltage to zero ON state current and turns OFF at zero ON state current to a finite blocking voltage. The zero voltage switching is the dual of the zerocurrentswitching process. In either case the switching loss is substantially reduced. The zerocurrent or zero voltage switching is achieved by switching close to the resonant frequency of the load (resonant load converter), or by addition of resonant elements to the switch (resonant switch converters) or by forcing a resonant transition during the switching process (resonant transition). SMPS employing resonant converters are not without drawbacks. For example, the ratio of the total installed VA of the various components to the output power - i.e. utilisation of the components - is generally poorer than with PWM type of SMPS. However, because of their many attractive operational features, resonant mode SMPS have taken up an appreciable share of the SMPS market [1-4].
The circulation of primary current is decrease conduction losses and decrease phase shift converter of conventional process. The soft switching operations are supported for additional resonant network. It is includes variation of load with input voltage process. The transformer is regenerate and used device switching then it is connect to side of lagging leg. In the time of load is high and input is low power efficiency is calculated as heavy in the proposed converter process. The design operations are analyzed and verified efficiency of power. The full load process is defined high efficiency power. The recovery of energy circuit is used phase-shift converters of conventional process. Additional resonant network is includes topology of power conversion methods. Simple auxiliary resonant circuit (SARC) is used R-load and RL-stack. The zero voltage switching (ZVS) and zerocurrentswitching (ZVC)are used to operate circuits of main switch process.CSO algorithm is used PI controller then boost converter soft switching results are produced by the R-load and RL-load .It is decrease loss of the boost converter soft switching process. The boost converter of hard switching process is used CSO (cat swarm optimization) algorithm process.
Abstract—In megahertz switching frequency, the effect of loss is significant. In diode-clamped resonant gate driver circuit, the resonant inductor current, duty ratio and dead time are the limiting parameters which bring implications to the switching loss and hence total gate drive loss. The experimental analysis has been carried out to validate the simulation results. From the predetermined inductor current of 9 nH, duty ratio of 20 % and dead time of 15 ns, remarkably, the experimental results show less than 10 % difference in value compared to the simulation. Therefore, this new finding validates that by using correct choice of these values, the diode-clamped resonant gate driver can operate better in higher switching frequency.
The work proposes a single-switch resonant boost converter which can be implemented in photovoltaic energy generation systems. Fig.1 shows the basic circuit diagram of proposed resonant converter. The converter consist of an active power (MOSFET) switch operated with ZVS and an energy blocking diode operated with ZCS. Other components include a choke inductor L m , a shunt capacitor C, a resonant inductor L s , an energy-blocking diode D, and
Most high-frequency electronic ballasts have load resonant inverters that provide ignition voltage and a stable lamp current with a low crest factor for fluorescent lamps. Furthermore, load resonant inverters can operate at very high switching frequencies and have low switching losses and electromagnetic interference (EMI). To enhance the efficiency of high-frequency electronic ballasts, many soft-switching technologies have been developed [11-15]. The class-E zero voltage- switching (ZVS) resonant inverters have the highest efficiency of all existing resonant inverters. The class-E ZVS resonant inverter has a single-ended structure and, thus, is unlike class-D ZVS inverters, which have a double- ended output and, thus requires two separate gate trigger signals and an upper trigger signal that has an isolated circuit. Additionally, the trigger circuit in the class- E topology, which has a single end, is simple. Consequently, the class-E ZVS resonant inverter has recently become common in switchmode power applications. The use of a class-E ZVS resonant inverter as a fluorescent lamp ballast has such advantages as few components, low cost and high power density. These characteristics, combined with the fact that the class-E ZVS resonant inverter has only one active power switch, result in electronic ballast with a very simple structure, low switching losses, small volume and light weight. Additionally, as commutations in the active power switch of the class-E resonant inverter are performed at zero voltage, electronic ballast switching losses are extremely low, resulting in very high efficiency.
Abstract—This paper does the analysis of different passive snubber in soft switched boost converters with the help of SIMULINK. Here comparison of the converters with passive snubber have been done to determine which one is efficient in terms of performance such as efficiency, voltage stress, complexity etc. In this paper two types of passive snubber associated with boost converters are first discussed, then the respective converters are analyzed which includes simulation of the two topologies under the same conditions. This paper should act as a benchmark for future work in the dais of passive snubber. Keywords— Boost converter, passive snubber, soft – switched, zero voltage switching, zerocurrentswitching
A two-phase soft switched interleaved boost with simple auxiliary commutation circuit is shown in Figure 1. The two input inductors are of same value and closely coupled to each other. The conduction losses in the for- ward path are greatly minimized by the input current equally divided into two paths through the coupled induc- tor arrangement. The main switches and the added auxiliary switches are switched at ZVS during turn-on transi- tion and ZCS during turn-off transition. The proposed converter has the following features:
Fig. 1 shows the block diagram of proposed system of resonant inverter topology and Fig.2 shows a circuit diagram of an APWM resonant inverter, which consists of a chopper, a series-parallel resonant circuit, a Second harmonic trap and a high-frequency transformer. The chopper converts input dc voltage into a high frequency unidirectional voltage at its output. The control circuits and driver circuits are used to generate the driving pulses. These driving pulses are used to make the chopper ON and Off. The resonant circuit consists of a series branch and a parallel branch. To achieve zero voltage Switching (ZVS) and maximum power transfer, the series resonant branch is tuned at the operating frequency, and the parallel Branch is off-tuned to provide inductive impedance at the operating frequency.
Abstract- A closed loop control of the fourth order (LCLC configuration) resonant converter has been simulated and presented in this paper. The PI controller has been used for closed loop operation and the performance of proposed converter has been estimated with the closed loop and the open loop condition. The steady state-transient responses of nominal load, sudden line and load disturbances have been obtained to validate the controller performance. The proposed approach is expected to provide better voltage regulation for dynamic load conditions.
Abstract: The purpose of this paper is to compare the performance of the conventional buck converter and the resonant buck converter. The input supply given to the power electronics converter will be the battery of 48VThe resistive load is connected at the output of the converter. The dc-dc converter is controlled by using the PWM technique. In resonant converter with respect to the load the power electronics switches will not experience any current stress or voltage stress. Simulation outputs are provided. Simulation is done by MATLAB/SIMULINK software.
boost dc-dc converter. Passive soft-switching is employed due to its advantages over the active soft-switching and its ability to reduce switching losses. A Laplace transform- based analysis of the converter circuit is carried out to obtain design information. Experimental results obtained from the prototype agree closely with the predicted results and demonstrate the feasibility of the system.
Recently the growth of battery powered applications are increasing for the demand of high step up dc-dc converters. A dc-dc boost converter are used because of high efficiency and easy circuitry. The solar array, fuel array etc. All these applications has low output voltage. So foe these applications high step up dc-dc boost converter with high voltage gain is necessary and boost converter is able to provide high voltage gain. But general boost converter operates at extreme high duty cycle and hard switching operation, increases the diode reverse recovery problems. So in order to compensate all these drawbacks a new Resonant Pulse Width Modulation Technique (RPWM) converter is designed. This proposed converter increases the output voltage and also reduces the diode reverse recovery problems. Early hard switching technique is also used but it increases the voltage stress across the switches reduces the efficiency. So for this purpose soft switching technique is used. This technique consist zero voltage and zerocurrentswitching (ZVZCS) operation. This technique reduces the losses across switches and increases the circuit performance.
MCs are used to convert AC mains inputs to an AC output with a different frequency and amplitude directly without any intermediate conversion stage. In order to generate a high-frequency current on the primary side, specific power converters are employed in IPT systems.However, in recent years, there has been an increasing interest in matrix converters . In MCs, the bulky energy storage elements are eliminated and thereby, they have high power density and are more reliable. Specifically, three-phase to single-phase and single-phase to single-phase MCs are of great interest in Inductive Power Transfer systems. A direct soft-switched single-phase ac–ac matrix converter (MC) for bidirectional inductive power transfer (IPT) systems is proposed.
ABSTRACT: An approach of zero-current-switching (ZCS) for main switches are presented in this project. Different from the large turn-off current of main switches of the conventional zero-voltage and zero-current-switching (ZVZCS) full-bridge (FB) dc-dc converter, small turn-off current of auxiliary circuit is introduced to achieve ZCS for main switches, where the auxiliary circuit also delivers a small portion power and can realize ZVZCS. Hence, high efficiency can be achieved with the switching loss lowered remarkably. Furthermore, a hybrid resonant FB dc-dc converter is proposed, the operation principle and parameters design rules of which are analyzed in detail. A experimental platform has been built to verify the feasibility and performance of the proposed ZCS approach, as well as the proposed converter.
In modern power electronics technology, Power Factor Correction (PFC) technology has been studied and applied widely. The input current is tracked with the input voltage strictly by the control circuits in PFC converters, so as to improve the power factor and suppress harmonic currents effectively. However, with the increase of the input frequency, the phenomenon of input currentzero-crossing distortion would occurs, and the higher the input frequency is, the distortion phenomenon will be more serious  .The airborne AC power system is 115V/400Hz, the distortion phenomenon is more obvious in this high-frequency and the THD is higher. It is faced with much difficulty to meet the harmonic current standard GJB181B-2012  in airborne system.
The system development starts with the design specification of the proposed design. Block diagram has been used to outline the proposed design as shown in Figure 3:3. there are several components that have been identified in these projects which are the DC supplies, 7-level multilevel inverter, LC-Filer, non-linear load of the system which is the full wave bridge rectifier and the microcontroller which works as the controller system of the multilevel inverter. The components inside the microcontroller software system include the proposed controller which is the proportional-resonantcurrent controller, the Pulse Width Modulator (PWM) for the inverter circuit and a pulse generator to generate the switching pulse for the rectifier. The AC current at the output of the LC-filter will be measured using current transducer. It will be taken as the feedback signal for the current control system in the microcontroller.
To provide a regulated negative voltage, the PWM buck-boost converter, and switched capacitor converters (SCCs) are employed classically. Quasi-resonant buck-boost converter is a soft switching counterpart of PWM buck-boost converter in which a high-frequency resonant tank is utilised to reduce switching losses. The main advantage of this technique is its less additional elements. To provide a fractional voltage gain, many diodes and capacitors ought to be used, which result in an increase of the converter cost, volume and conduction losses [7, 8]. Resonant converters are a family of soft-switching converters, in which energy is transferred through a high frequency resonant tank and switching is performed at zero-crossing instants of current and/or voltage.