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This paper presents a bootstrap driver that can operate a normally-on, a depletion-mode, GaN FET power device as a normally-off device. The bootstrap driver based on a diode-clamp circuit which is composed of a capacitor and a diode, shifting the input voltage by a negative amount (−10V) to turn off the power switch with a negative threshold (−8V). However, due to the clamp capacitor discharge by...
This paper proposes a new modular multilevel converter with symmetric bidirectional DC fault blocking capability for high voltage direct current transmission systems. The new modular multilevel converter is composed of novel submodules, which is developed from a three-level T-type converter combined with some clamp circuits. The proposed novel submodule can output three voltage levels with six IGBTs,...
A new three-phase DC-DC PWM boost converter that is suitable for use in renewable energy applications is proposed in the paper. The number of components in the proposed circuit is fewer that other previously proposed converters of the same type, resulting in lower cost and simpler operation. The paper presents the new converter and discusses its operation, features and design. Experimental results...
An interleaved current-fed capacitor-less DC/AC converter for PV systems is proposed in this paper with the merits low input current ripple, high power density and high reliability. This proposed DC/AC converter is composed of an interleaved current-fed dc/pulsating-dc converter cascaded with a three-phase pulsating-dc/ac inverter through pulsating-dc-link modulation. The pulse width modulation of...
Grid connected PV systems are the most popular solar electric system on the market today. The most important device in the grid-connected PV system is the inverter. This paper presents a survey on the grid connected PV inverters and the system topologies used for grid connected PV system. The review describes different two level inverter topologies as well as multilevel inverter topologies. Cascaded...
A new three-phase DC-DC PWM boost converter that is suitable for use in renewable energy applications is proposed in the paper. The number of components in the proposed circuit is fewer that other previously proposed converters of the same type, resulting in lower cost and simpler operation. The paper discusses the operation of the converter, presents a procedure for its design, and demonstrates the...
Flyback converters are widely used in telecom applications with two of the most popular being in point-of-use power supplies and as part of two-stage AC-DC converters. They can be implemented with either passive snubbers or active snubbers for the main converter switch. Active snubbers are generally thought to be more efficient but more expensive than passive snubbers, but recent developments in passive...
Output impedance of active-clamp converters is a valid method to achieve current sharing among parallel-connected power stages. Nevertheless, parasitic capacitances result in resonances that modify converter behavior and current balance. A solution is presented and validated. The current balance is achieved without a dedicated control.
In this work, four different snubber solutions for an Auxiliary Resonant Commutated Pole (ARCP) converter with an auxiliary thyristor are evaluated. The first two solutions are an RC snubber and a variation thereoff where the RC snubber losses are reduced by employing diodes for limiting the voltage overshoot. Two other concepts are a novel lossless dV/dt clamp snubber circuit and a low-loss RC snubber...
Super capacitor energy storage system(SCESS) with high power, long life, wide operating temperature range, is widely used in industrial applications. The balancing system is needed to ensure the operation safety of the SCESS. In this paper, the balancing system based on active clamped forward converter is designed. The active clamped forward converter is based on synchronous rectifier technology with...
Large-scale photovoltaic(PV) generation system connected to HVDC grid has many advantages compared to its counterpart of AC grid. DC connection can solve many problems that AC connection faces, such as the grid-connection and power transmission, and DC connection is the tendency. DC/DC converter as the most important device in the system, which has become one of the hot spots recently. There are many...
This paper is concerned with the process of current commutation and overvoltage protection in matrix converters. The mechanisms involved in the commutation process and clamp circuit are described and simulation waveforms are presented. A four-step semi-soft commutation strategy is described that this technique relies on knowledge of the output current direction and the ability to control the direction...
A start up method is presented, which is suitable for a single-phase single-stage full-bridge boost PFC converter with multiple-level clamp circuits. In this converter, the flyback inductors are added to the boost inductor and the coupled inductor respectively. When starting, it operates in flyback mode, and the output capacitor is charged by the adding inductors. Operational principle of this converter...
In this paper, the ultrahigh step-down converter with an active clamp circuit is proposed. With the active clamp circuit, the voltage spike across the central-tapped switch can be suppressed. The switches can achieve zero-voltage-switching (ZVS) turn-on or zero-current-switching (ZCS) turn-off. Finally, theoretical analysis and experimental results are given to verify the feasibility and effectiveness...
This paper presents a transient analysis of various configurations of DC distribution systems. A combination of theoretical and practical methods were used to investigate the behavior of the system's variables after the occurrence of faults and the protection operation. A number of networks of varying complexity were built with detailed cable models using the EMTP/ATP software package in order to...
A novel Taiwan Tech Multi-Level Converter (TMC) is proposed for high-voltage input power conversion applications. A basic two-level circuit is obtained by modifying the conventional half-bridge converter with a dual-primary transformer and a clamping capacitor. By stacking N multi-level cells (MLC, each with two capacitors and two series switches) inserted into two-level circuit, consequently, a desired...
A novel high step-up DC-DC converter with ZVS turn-on switches and ZCS turn-off diodes based on several existed techniques such as coupled-inductor, active clamping, stacked capacitor and interleaved technique is designed and implemented in this paper. The main objective of proposed circuit is soft-switching operation. The leakage inductance of coupled inductors resonates with two secondary-side capacitors...
Renewable energy is gaining more attention because conventional power plants are facing several environment problems. In the present scenario, wind power grid interfacing is one of the favorable approaches for electricity production. This paper introduces the MATLAB modeling and simulation of 5-Level and 3-Level neutral point clamped inverters for grid interfacing using SEPIC converter for wind energy...
A high-voltage-gain technique employing dc-dc power electronic converters is proposed. The suggested topologies can be used as multiport converters and draw continuous current from two input sources. They can also draw continuous current from a single source in an interleaved manner. The proposed converter can easily achieve a gain of 12 while getting a continuous input current. Such a converter can...
The following work introduces the use of a modified four-level medium voltage converter in a back-to-back configuration for its application on wind energy conversion systems (WECS). The proposed converter topology is based on a three-level neutral-point clamped converter (3L-NPC) without clamping diods or power switches, so that dc-link capacitors are in a floating condition respect to the neutral...
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