New Fully Soft-Switched Boost-Converter with Reduced Conduction Losses

Abstract

A new fully soft-switched boost-converter is proposed mentioned above, but the turn-off of the single auxiliary switch here, using only one auxiliary switch. All switches used in this will not be with proper ZVS. The topology presented in [6] is converter turn on and turn off under fully soft-switched superior than others in terms of switching behaviour of the condition. The diodes also commutate softly. The converter uses switches, but the auxiliary circuit requires isolated gate drive. minimum number of components in the auxiliary circuit without additional current stress of the main switch. The circuitIn the present work, a new boost converter has been conduction losses are also minimised, since the resonant proposed using only one auxiliary switch in which all switches capacitor charging current flows only through an inductor and a operate under fully soft-switched condition without any diode. The main and auxiliary IGBT share a common emitter additional current stress of the main switch. Moreover, the connection, facilitating direct drive to them. The circuit is circuit involves minimum number of components in the path suitable for application to active power factor correction. Various for charging and discharging of resonant capacitor. Hence, the operating modes of the converter are presented and analysed. soft-switching is achieved with reduced conduction losses and The principle of operation has been verified with computer the diodes also commutate softly. Both the switches used in simulation and experimental results. this converter turn on under ZCS condition. The main switch is turned off under zero-voltage, zero-current condition. The Keywords-Boost converter; Power factor correction; soft auxiliary switch tum-off is also with zero voltage although no switching; ZVS; ZCS.capacitance is needed to be in parallel with the device. Thus, IGBTs are best suited for this application as its inherent I. INTRODUCTION parallel capacitance is very small. Here the parallel capacitor The PWM boost converter is widely used as a dc-dc required for ZVS turn-off is fulfilled by the discrete resonating converter and as a power factor correction (PFC) pre-regulator capacitor C, connected in series with the switch. for power supplies. The boost converter operated in the continuous conduction mode, is in fact the most popular II. PRINCIPLE OF OPERATION topology used in industry today for PFC. This converter, The proposed soft-switched boost converter as shown in Fig. however, has several problems due to the reverse recovery of Iuses an auxiliary network in addition to the boost inductor the boost diode and the switching losses associated with the switch. These two effects create a significant amount of power L5, boost switch S and boost diode D3. The auxiliary dissipation and high EMI in high frequency hard-switch network consists of one switch S2I one diode D2, two applications. To overcome these problems, several techniques inductors L1 and L2 and one resonant capacitor Cr. The output have been developed, using additi...

High Frequency Boost Converter Employing Soft Switching Auxiliary Resonant Circuit

“…When the resonant inductor current (iLr ) is equal to the main inductor current at t2 , mode 2 completes and the resonant inductor voltage equals the output voltage. Thus, the resonant inductor current is expressed by (5). The main inductor current decreases and, at the end of this mode, the main inductor current is equal to the minimum, as defined by (6).…”

Three‐level boost converter with zero voltage transition

“…For the switch‐resonant converters, they use the resonant tank connected with switches to achieve soft switching. These switch‐resonant converters can be classified into general mode [14–17], full‐wave mode [18–20], half‐wave mode [21–23], active clamp [24–36], zero voltage transition (ZVT) [37–48], zero current transition [49–51], and ZCTZVT [52, 53].…”