The growing trend in power demand and efficiency requirements of modern telecommunication systems is in need of PFC converter at the front end. The presence of non-linear loads results in poor power factor. Also, there is a need to reduce... more
The growing trend in power demand and efficiency requirements of modern telecommunication systems is in need of PFC converter at the front end. The presence of non-linear loads results in poor power factor. Also, there is a need to reduce the ripple present at both the input and output end of the DC to DC boost converter so as to improve the supply power factor of the system. This paper reveals a comparative study of ripple present in inductor current, output current and output voltage of three different topologies of DC-DC converters namely dc-dc boost converter, interleaved boost converter and soft switching interleaved boost converter. This paper also highlights the significance of each converter by computing the efficiency. The simulated waveforms have been demonstrated using MATLAB/SIMULINK. The performance of three different dc-dc boost converter topologies is investigated and the results are verified. The results reveal that soft switched gives a higher efficiency compared to the other topologies.
This paper proposes the design and experimentation of digital control of soft-switched interleaved boost converter using FPGA for Telecommunication System. The switching devices in the proposed converter are turned on and off with Zero... more
This paper proposes the design and experimentation of digital control of soft-switched interleaved boost converter using FPGA for Telecommunication System. The switching devices in the proposed converter are turned on and off with Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) respectively. The circuit is operated in Continuous Conduction Mode (CCM) with various load ranges having duty cycle of more than 50%. The proposed converter is studied by developing the simulation module in MATLAB/SIMULINK. A PI controller is designed and implemented in FPGA to obtain a regulated DC output for line and load variations. Simulation and experimentation results are verified with a prototype development of the proposed converter. The results indicate that the converter performance is enhanced with closed loop control.
In this work, interface using DC-DC high Step-up non-transformer resonant converter for grid connected Non-conventional energy sources is proposed. It is a promising option to make use of renewable energy sources to be connected to HVDC... more
In this work, interface using DC-DC high Step-up non-transformer resonant converter for grid connected Non-conventional energy sources is proposed. It is a promising option to make use of renewable energy sources to be connected to HVDC grid which require high voltage & high power renewable energy sources. A dc-dc step-up converter is used as major equipment which operates as a resonant converter with high voltage gain. The voltage stress on the semiconductor devices & switching losses is reduced by zero voltage switching (ZVS) turn-on and turn-off method and also with zero current switching (ZCS) turn-off of converter switches. The selection of required parameters for the dc-dc step-up resonant converter is presented in this paper. The proposed converter system operation, performance and simulation results have been successfully verified by using MATLAB/Simulink. Keywords: dc-dc step-up converter, parallel LC resonant tank, soft switching (zero voltage & zero current)
Abstract—This paper proposes a family of soft switching bidirectional converters. In many applications, the bidirectional converters operate over a wide range of duty-cycle and load variations. In the proposed converters, in order to... more
Abstract—This paper proposes a family of soft switching bidirectional converters. In many applications, the bidirectional converters operate over a wide range of duty-cycle and load variations. In the proposed converters, in order to extend the ZVS operation range, two supplemental voltage sources utilizing passive components are implemented in the auxiliary circuit. By using this method, the soft switching features are ensured for an extensive range of the converter duty-cycles. This is achieved independent of the output power value or the converter operation mode and so, soft switching is ensured within the entire converter operating region. In these converters, all semiconductors components are soft switched, and the auxiliary circuit does not contribute to the complexity of the control circuit. Also, no extra voltage stress exists on the main switches and the voltage stress on the auxiliary switches is lower than the main switches voltage stress. In this paper, the proposed bidirectional buck/boost converter is analyzed and to confirm the feasibility of the proposed method, experimental results of a 150-W prototype converter are presented. Index Terms—Pulse width modulation (PWM) dc-dc converters, Bidirectional dc–dc converter (BDC), soft-switching techniques, zero-voltage switching (ZVS), zero-voltage switching (ZVT).
A family of soft-switching power converter is presented for fuel cell applications. The salient points are that all the switching devices are under zero-current switching during turn-on and zero-voltage switching during turn-off. The... more
A family of soft-switching power converter is presented for fuel cell applications. The salient points are that all the switching devices are under zero-current switching during turn-on and zero-voltage switching during turn-off. The family of the circuit presented includes the buck, boost, buck-boost and Cuk converter. The active switches in the converter undergo zero-capacitive turn-on losses unlike switches in other soft-switched topologies discussed in the literature. The switches do not experience any over voltage/over current stress proportional to load as in resonant converters. This soft-switching technique can also be applied to other classical switched mode power converters. A detailed mathematical analysis of the converter under steady state is carried out, and experimental results obtained from a prototype are presented. The converter was also connected to a model toy car driven by fuel cells for the demonstration of the application.
In this paper, a new family of zero-voltage-transition bidirectional converters are introduced. In the proposed converters, soft switching condition for all semiconductor elements is provided regardless of the power flow direction and... more
In this paper, a new family of zero-voltage-transition bidirectional converters are introduced. In the proposed converters, soft switching condition for all semiconductor elements is provided regardless of the power flow direction and without any extra voltage and current stress on the main switches. The auxiliary circuit is composed of a coupled inductor with the converter main inductor and two auxiliary switches. The auxiliary switches benefit from significantly reduced voltage stress and without requiring floating gate drive circuit. Also, by applying the synchronous rectification to the auxiliary switches body diodes, conduction losses of the auxiliary circuit is reduced. In the auxiliary circuit, the leakage inductor is used as the resonant inductor and all the magnetic components are implemented on a single core which has resulted in significant reduction of the converter volume. In the proposed converters, the reverse recovery losses of the converter rectifying diodes are completely eliminated and hence, using the low-speed body diode of the power switch as the converter rectifying diode is feasible. The theoretical analysis for a bidirectional buck and boost converter is presented in details and the validity of the theoretical analysis is justified using the experimental results of a 250W prototype converter.
This paper is mainly concerned with the state-of-the-art feasible development of a novel prototype high-efficiency phase-shift soft-switching pulse modulated full-bridge DC-DC power converter with a high-frequency power transformer, which... more
This paper is mainly concerned with the state-of-the-art feasible development of a novel prototype high-efficiency phase-shift soft-switching pulse modulated full-bridge DC-DC power converter with a high-frequency power transformer, which is designed for utility-grid tied photovoltaic (PV) power inverters. The proposed high-frequency transformer (HFTR) link DC-DC converter topology is based upon a new conceptual secondary-side series resonant principle and its inherent nature. All the active power switches in the HFTR primary-side can achieve lossless capacitive snubber-based ZVS with the aid of transformer parasitic inductances. In addition to this, passive power switches in its secondary-side can also perform ZVS and ZCS transitions for input voltage and load variations. In the first place, the operation principle of the newly-proposed DC-DC converter and some remarkable features are described in this paper on the basis of the simulation analysis. In the second place, the 5 kW experimental setup of the DC-DC converter treated here is demonstrated and its experimental results are illustrated from a practical point of view. Finally, some comparative evaluations between simulation and experimental data are actually discussed and considered in this paper, together with its future works.
In this paper, an interleaved soft switching boost converter employing ZVS and ZCS principle leads to reduce ripple contents and high efficiency is proposed for renewable energy systems (RES).The conventional hard-switched interleaved... more
In this paper, an interleaved soft switching boost converter employing ZVS and ZCS principle leads to reduce ripple contents and high efficiency is proposed for renewable energy systems (RES).The conventional hard-switched interleaved converter results in increased switching losses and ripples. To overcome, this drawback, a two-phase Interleaved Boost Converter (IBC) with ZVS and ZCS is proposed. This circuit consists of two identical boost converter connected in parallel and are controlled by interleaved switching signals.The circuit is analyzed in Continuous Conduction Mode (CCM) with various load ranges having duty cycle of more than 50%.Simulation studies of the proposed converter is carried out in MATLAB. The performance parameters such as output voltage ripple, output current ripple, inductor current ripple and efficiency of the proposed converter is computed to show the significance of the soft switching principle.The results are verified.
—A new dc–dc converter with only one active switch operating at a constant switching frequency and with low-current and voltage stress is proposed. The conduction losses are minimized because of the ability to use a minimum number of... more
—A new dc–dc converter with only one active switch operating at a constant switching frequency and with low-current and voltage stress is proposed. The conduction losses are minimized because of the ability to use a minimum number of elements in the path of direct energy transfer from the input to the load. Furthermore, because only one switch is used, the design of the control circuit is greatly simplified. The new converter achieves soft switching for the diodes and zero-current switching (ZCS) at turn on for the active switch. Index Terms— Quasi-resonant converter (QRC), zero-current switching (ZCS), zero-voltage switching (ZVS).
Inverters with thyristors need auxiliary turn off circuits. But even in the case of GTOs or IGBTs, an auxiliary turn off circuit has been used to reduce turn off losses. The calculation of the optimal values of the passive commutating... more
Inverters with thyristors need auxiliary turn off circuits. But even in the case of GTOs or IGBTs, an auxiliary turn off circuit has been used to reduce turn off losses. The calculation of the optimal values of the passive commutating components (C and L), and the commutating current is usually done by means of equations found by graphical or empirical methods. This article shows a completely analytic method, which gives more accurate results.
In this paper, a novel high conversion ratio DC-DC converter suitable for photovoltaic applications is presented. Utilizing single-switch and single-magnetic core, low ripple input current and low voltage stress across the semiconductors... more
In this paper, a novel high conversion ratio DC-DC converter suitable for photovoltaic applications is presented. Utilizing single-switch and single-magnetic core, low ripple input current and low voltage stress across the semiconductors are the major advantages of the proposed converter. In order to provide soft-switching condition for the converter switch at a wide range of output power, a passive lossless snubber is employed. The presented converter is adequate for photovoltaic applications due to mentioned properties. Operating principles are analyzed and design considerations are provided. In order to validate the theoretical analysis, a prototype of the proposed converter is implemented and the experimental results are exhibited.
In this study, a novel sinusoidal PWM switched AC/DC/AC converter interface scheme using real novel triloop voltage error tracking fuzzy logic controller (FLC), to stabilize the stand alone Wind Energy Conversion Scheme (WECS) using an... more
In this study, a novel sinusoidal PWM switched AC/DC/AC converter interface scheme using real novel triloop voltage error tracking fuzzy logic controller (FLC), to stabilize the stand alone Wind Energy Conversion Scheme (WECS) using an induction generator. The proposed novel sinusoidal Pulse Width Modulator (SPWM) switched (AC/DC/AC) converter (diode rectifier and 6-pulse IGBT inverter) interface scheme serves as a combined voltage stabilization regulator and maximum wind energy utilization and enhancement compensator.
This paper presents a novel dc-dc converter with adaptive soft switching as a means to achieve ZVS operation for all the switches. It adopts phase shift modulation features for constant frequency operation and adaptive soft switching at... more
This paper presents a novel dc-dc converter with adaptive soft switching as a means to achieve ZVS operation for all the switches. It adopts phase shift modulation features for constant frequency operation and adaptive soft switching at low load. To accomplish this task two loops are employed; inner current control loop is to check the loading condition and turn on of auxiliary switch accordingly. Outer control loop is used to improve the dynamic performance of DC-DC converter by achieving a robust output voltage against load disturbances. This paper also presents the performance of various controllers. A 1kW/100KHz dc/dc converter is simulated and analyzed. Performance of the proposed topology is evaluated at different loads i.e. static and dynamic load (DC motor). An efficiency comparison of the converter with a reported topology has also been carried out.
