The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A review of high voltage gain, high efficiency bidirectional dc-dc topologies is presented. Each converters primary benefit is highlighted, and a summary of all the converters is presented. It is observed that voltage gains higher than 20 is only achieved with topologies using a transformer. The average efficiency of the topologies is slightly lower for isolated topologies. Different strategies are...
This paper presents a comparative evaluation of the loss and thermal performance of two advanced three-level inverter topologies, namely the SiC based T-Type and the Hybrid-NPC, both of which are aimed at reducing the high switching losses associated with a conventional Si based T-Type inverter. The first solution directly replaces the 1200V primary Si IGBT switches with lower loss 1200V SiC MOSFETs...
A new method is implemented in designing of self-oscillating loop for driving piezoelectric transformers. The implemented method is based on combining both analog and digital control systems. Digitized delay, or digitized phase shift through the self-oscillating loop results in a very precise frequency control and ensures an optimum operation of the piezoelectric transformer in terms of voltage gain...
This paper gives a comprehensive comparison of two promising silicon carbide (SiC) switching devices, i.e. normally-off SiC MOSFET and a normally-on SiC JFET, as alternatives to a conventional state of the art Si IGBT. The comparison uses datasheet information to determine conduction losses, switching transition measurements for switching loss calculations and electrical power measurements in a boost...
This paper presents the loss performance analysis of an isolated power supply that is designed for ultra-fast tracking converters. The results of the analysis provide insights into the operation of the proposed power supply, how each physical component contributes to the total loss, and how its efficiency may be further improved.
In this paper, an efficiency comparison of neutral-point-clamped (NPC) inverters and bipolar switch NPC (T-Type) inverters is studied and the result shows that the T-Type inverter is more efficient at lower switching frequencies. Nevertheless, its efficiency suffers when the switching frequency increases due to high switching loss of the equipped high voltage power switches. In order to reduce switching...
Inductorless switch mode power supplies based on piezoelectric transformers are used to replace conventional transformers in high power density switch mode power supplies. Even though piezoelectric-based converters exhibit a high degree of nonlinearity, it is desirable to use piezoelectric transformers due to their smaller size, lighter weight, lower electromagnetic interference, higher power density,...
This paper presents a digital control technique to achieve valley switching in a bidirectional flyback converter used to drive a dielectric electro active polymer based incremental actuator. The incremental actuator consists of three electrically isolated, mechanically connected capacitive actuators. The incremental actuator requires three high voltage (∼2.5 kV) bidirectional DC-DC converters, to...
This work considers an alternative method of reducing the body diode reverse recovery by taking advantage of the MOSFET body effect, and applying a bias voltage to the gate before reverse recovery. A test method is presented, allowing the accurate measurement of voltage and current waveforms during reverse recovery at high di/dt. Different bias voltages and dead times are combined, giving a loss map...
This paper examines different winding strategies for reduced capacitance inductors in active power factor correction circuits (PFC). The effect of the parasitic capacitance is analyzed from an electro magnetic compatibility (EMI) and efficiency point of views. The purpose of this work is to investigate different winding approaches and identify suitable solutions for high switching frequency/high speed...
Three-port converter (TPC) topologies for renewable energy systems aim to provide higher efficiency and power density than conventional cascaded structures. This work proposes an analytical comparison of different TPC topologies for a photovoltaic LED lamp stand-alone system. A comparison using component stress factor (CSF) is performed, which gives a quantitative measure of the performance of the...
This paper presents a new self-oscillating resonant gate drive composed solely of passive components. The gate drive can be used in various resonant converters and inverters and can be used for both low and high side gate drive. The paper presents examples of how higher order harmonics can be used to improve the performance of the gate drive and how the gate drive can be implemented in a class E inverter,...
This paper presents a guide on characterizing state-of-the-art silicon superjunction (SJ) devices in the 600V range for single phase power factor correction (PFC) applications. The characterization procedure is based on a minimally inductive double pulse tester (DPT) with a very low intrusive current measurement method, which enables reaching the switching speed limits of these devices. Due to the...
A hysteretic self-oscillating bandpass current mode control (BPCM) scheme for Class D audio amplifiers driving capacitive transducers are presented. The scheme provides excellent stability margins and low distortion over a wide range of operating conditions. Small-signal behavior of the amplifier is analysis through transfer function based linear control methodology. Measurements are performed on...
This paper presents a bidirectional dc/dc converter operated with batteries both in the input and output. Primary parallel isolated boost converter (PPIBC) with transformer series connection on the high voltage side is preferred due to its ability to handle high currents in the low voltage side. The converter has been modeled using non-ideal components and operated without any additional circuitry...
In this paper, a modulation strategy based on the circuit-level decoupling concept is proposed and investigated for the three-level four-leg neutral-point-clamped (NPC) inverter, with the aim of delivering power to all sorts of loads, linear/nonlinear and balanced/unbalanced. By applying the proposed modulation strategy, the four-leg NPC inverter can be decoupled into three three-level Buck converters...
This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS's (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits, modulation schemes, LEDs and LED driving conditions are analyzed. A prototype radial mode PT optimized for ZVS...
In this paper, a circuit-level decoupling modulation strategy is proposed for the three-level (TL) neutral-point-clamped (NPC) inverters. With the proposed modulation scheme, the TL-NPC inverter can be decoupled into two three-level Buck converters in each defined operating section, which makes the controller design much simpler. The decoupling principle including the driving signal synthesis and...
This paper evaluates eight module inverter topologies and provides an overview of the merits and demerits of each on the basis of circuit level Pspice simulation. The complete system is modeled in Pspice and the model is made as realistic as possible by including the parasitic elements. Only the output stage is varied for different topologies keeping the system model unaltered with the same control...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.