Showing papers on "Rectifier published in 2007"

Interleaved Boost Converter With Intrinsic Voltage-Doubler Characteristic for Universal-Line PFC Front End

Abstract: A novel, two-inductor, interleaved power-factor-corrected (PFC) boost converter, that exhibits voltage-doubler characteristic when it operates with a duty cycle greater than 0.5 is introduced. The voltage-doubler characteristic of the proposed converter makes it quite suitable for universal-line (90-264 VRMS) PFC applications. Because the proposed PFC boost rectifier operates as a voltage doubler at low line, its low-line range efficiency is greatly improved compared to that of its conventional counterpart. The performance of the proposed PFC rectifier was evaluated on an experimental 1.3-kW universal-line PFC prototype.

Analysis and Design Strategy of UHF Micro-Power CMOS Rectifiers for Micro-Sensor and RFID Applications

Abstract: Design strategy and efficiency optimization of ultrahigh-frequency (UHF) micro-power rectifiers using diode-connected MOS transistors with very low threshold voltage is presented. The analysis takes into account the conduction angle, leakage current, and body effect in deriving the output voltage. Appropriate approximations allow analytical expressions for the output voltage, power consumption, and efficiency to be derived. A design procedure to maximize efficiency is presented. A superposition method is proposed to optimize the performance of multiple-output rectifiers. Constant-power scaling and area-efficient design are discussed. Using a 0.18-mum CMOS process with zero-threshold transistors, 900-MHz rectifiers with different conversion ratios were designed, and extensive HSPICE simulations show good agreement with the analysis. A 24-stage triple-output rectifier was designed and fabricated, and measurement results verified the validity of the analysis

Resistance Compression Networks for Radio-Frequency Power Conversion

Abstract: A limitation of many high-frequency resonant inverter topologies is their high sensitivity to loading conditions. This paper introduces a new class of matching networks that greatly reduces the load sensitivity of resonant inverters and radio frequency (RF) power amplifiers. These networks, which we term resistance compression networks, serve to substantially decrease the variation in effective resistance seen by a tuned RF inverter as loading conditions change. We explore the operation, performance characteristics, and design of these networks, and present experimental results demonstrating their performance. Their combination with rectifiers to form RF-to-dc converters having narrow-range resistive input characteristics is also treated. The application of resistance compression in resonant power conversion is demonstrated in a dc-dc power converter operating at 100MHz

Semiconductor device and power receiving device

Abstract: An object is to provide a semiconductor device that is capable of wireless communication, such as an RFID tag, which can transmit and receive individual information without checking remaining capacity of a battery or changing batteries due to deterioration with time in the battery for a drive power supply voltage, and maintain a favorable a transmission/reception state even when electric power of an electromagnetic wave from a reader/writer is not sufficient. The semiconductor device includes a signal processing circuit, a first antenna circuit connected to the signal processing circuit, an antenna circuit group, a rectifier circuit group and a battery connected to the signal processing circuit. The first antenna circuit transmits and receives a signal for transmitting data stored in the signal processing circuit and drives a power supply circuit, and each antenna circuit of the antenna circuit group receives a signal for charging the battery and includes an antenna which has a different corresponding frequency.

Apparatus and method of wireless power sharing by induction method

Abstract: An apparatus (100, 101, 102, 103, 104, 106) and method of wirelessly sharing power by an inductive method are provided. The apparatus includes a first battery (130, 131, 132, 133, 134, 136) supplying power; a rectifier (120, 121, 122, 123, 124, 126) supplied with an AC voltage, converts the AC voltage into a DC voltage, and outputs the DC voltage; an inverter supplied with the DC voltage, converts the DC voltage into the AC voltage, and outputs the AC voltage; a power control/conversion unit (110, 111, 112, 113, 114, 116) connected to the rectifier or the inverter and supplying power to charge the first battery or a second battery that is provided in an external device as a power supply for the first battery; and a communication unit (170, 171, 172, 173, 174, 176) communicating with the external device.

Electromagnetic Energy Harvesting Circuit With Feedforward and Feedback DC–DC PWM Boost Converter for Vibration Power Generator System

Abstract: This paper presents an integrated vibration power generator system. The system consists of a mini electromagnetic vibration power generator and a highly efficient energy harvesting circuit implemented on a minute printed circuit board and a 0.35-mum CMOS integrated chip. By introducing a feedback control into the dc-dc pulsewidth modulation (PWM) boost converter with feedforward control, the energy harvesting circuit can adjust the duty ratio of the converter following the variation of the input voltage and the voltage of energy storage element to get high energy conversion efficiency. The energy harvesting circuit rectifies the input ac voltage, steps up the dc output of the rectifier by the dc-dc PWM boost converter with feedforward and feedback control and stores the electric energy into a super capacitor, which can be used as a small electrical power supply for an intelligent micro sensor network

Rectifier circuit, power supply circuit, and semiconductor device

Abstract: It is an object of the present invention to provide a rectifier circuit that can suppress deterioration or dielectric breakdown of a semiconductor element due to excessive current. A rectifier circuit of the present invention includes at least a first capacitor, a second capacitor, and a diode which are sequentially connected in series in a path which connects an input terminal and one of two output terminals, and a transistor. The second capacitor is connected between one of a source region and a drain region and a gate electrode of the transistor. Further, the other one of the source region and the drain region and the other one of two output terminals are connected each other.

Dithering Skip Modulation, Width and Dead Time Controllers in Highly Efficient DC-DC Converters for System-On-Chip Applications

Abstract: This paper proposes temperature-independent load sensor (LS), optimum width controller (OWC), optimum dead-time controller (ODC), and tri-mode operation to achieve high efficiency over an ultra-wide-load range. Higher power efficiency and wider loading current range require rethinking the control method for DC-DC converters. Therefore, a highly efficient tri-mode DC-DC converter is invented in this paper for system-on-chip (SoC) applications, which is switched to sleeping mode at very light load condition or to high-speed mode at heavy load condition. The efficiency improvement is upgraded by inserting new proposed dithering skip modulation (DSM) between conventional pulse-width modulation (PWM) and pulse-frequency modulation (PFM). In other words, an efficiency-improving DSM operation raises the efficiency drop because of transition from PWM to PFM. Importantly, DSM mode can dynamically skip the number of gate driving pulses, which is inverse proportional to load current. Simplistically and qualitatively stated, the novel load sensor automatically selects optimum modulation method and power MOSFET width to achieve high efficiency over a wide load range. Moreover, optimum power MOSFET turn-on and turn-off delays in synchronous rectifiers and reduced ground bounce can save much switching loss by current-mode dead-time controller. Experimental results show the tri-mode operation can have high efficiency about 90% over a wide load current range from 3 to 500 mA. Owing to the effective mitigation of the switching loss contributed by optimum power MOSFET width and reduction of conduction loss contributed by optimum dead-times, the novel width and dead-time controllers achieve high efficiency about 95% at heavy load condition and maintain the highly efficient performance to very light load current about 0.1 mA.

Control of Single-Phase-to-Three-Phase AC/DC/AC PWM Converters for Induction Motor Drives

Abstract: This paper proposes a novel control scheme of single-phase-to-three-phase pulsewidth-modulation (PWM) converters for low-power three-phase induction motor drives, where a single-phase half-bridge PWM rectifier and a two-leg inverter are used. With this converter topology, the number of switching devices is reduced to six from ten in the case of full-bridge rectifier and three-leg inverter systems. In addition, the source voltage sensor is eliminated with a state observer, which controls the deviation between the model current and the system current to be zero. A simple scalar voltage modulation method is used for a two-leg inverter, and a new technique to eliminate the effect of the dc-link voltage ripple on the inverter output current is proposed. Although the converter topology itself is of lower cost than the conventional one, it retains the same functions such as sinusoidal input current, unity power factor, dc-link voltage control, bidirectional power flow, and variable-voltage and variable-frequency output voltage. The experimental results for the V/f control of 3-hp induction motor drives controlled by a digital signal processor TMS320C31 chip have verified the effectiveness of the proposed scheme

Electric vehicle and power feeding device for vehicle

Abstract: PROBLEM TO BE SOLVED: To provide an electric vehicle which receives charging power wirelessly from a power supply outside the vehicle by a resonating method and can charge a vehicle-mounted electric storage device. SOLUTION: An electric vehicle 100 has a secondary self-resonant coil 110, a second coil 120, a rectifier 130, and an electric storage device 140. The secondary self-resonant coil 110 is combined with a primary self-resonant coil 240 of a power feeding device 200 magnetically by resonance of a magnetic field and is capable of receiving a high frequency power from the first self-resonant coil 240. The secondary coil 120 is capable of receiving power from the secondary self-resonant coil 110 by electromagnetic induction. The rectifier 130 rectifies the power received by the secondary coil 120. The electric storage device 140 stores the power rectified by the rectifier 130. COPYRIGHT: (C)2009,JPO&INPIT

New Optimized PWM VSC Control Structures and Strategies Under Unbalanced Voltage Transients

Abstract: Control structures and strategies have a critical influence on a power electronic converter's behavior during disturbances. Most of the previous works in the field of pulsewidth modulation voltage-source converter (VSC) operation under unbalanced conditions propose dual vector controllers with dc bus voltage optimization strategies, which have been proven to be well adapted for rectifier applications. In this paper, two major contributions are made. On the one hand, a new optimized operation strategy based on exchanged power maximization is proposed for vector control structures, which permits the extension of optimized operation to other VSC applications (e.g., flexible alternating current transmission system and distributed generation interfaces). On the other hand, a scalar control structure is proposed based on resonant controllers, together with three adapted optimized operation strategies, namely: 1) dc bus voltage optimization; 2) power exchange maximization; and 3) a hybrid strategy (an intermediary mode between the other two strategies). Their main advantage is their simplicity and the lack of real-time symmetrical component extraction techniques. This scalar controller and the proposed optimized operation strategies are compared to conventional vector controllers. It is proven through experimental analysis that the proposed scalar controller offers very good performances with simpler structures and bigger flexibility in terms of operation modes.

High efficiency CMOS rectifier circuit with self-Vth-cancellation and power regulation functions for UHF RFIDs

Abstract: High efficiency CMOS rectifier circuit for UHF RFID applications has been developed The rectifier utilizes self Vth cancellation (SVC) scheme in which threshold voltage of MOSFETs is cancelled by applying gate bias voltage generated by output voltage of the rectifier itself Very simple circuit configuration and no power dissipation feature of the scheme enable excellent power conversion efficiency (PCE) especially in small RF input power conditions At higher RF input power conditions, PCE of the rectifier automatically decreases This is the built-in self-power-regulation function Proposed SVC CMOS rectifier has been fabricated with 035 mum CMOS process and the measured performance has been compared with other types of rectifiers The SVC CMOS rectifier achieves 29% PCE at -99 dBm RF input power condition This PCE is larger than ever reported rectifiers under the condition

Power Harvester Design for Passive UHF RFID Tag Using a Voltage Boosting Technique

Abstract: This paper presents a guideline to design and optimize a power harvester circuit for an RF identification transponder. A power harvester has been designed and fabricated in a CMOS 0.18- process that operates at the UHF band of 920 MHz. The circuit employs an impedance transformation circuit to boost the input RF signal that leads to the improvement of the circuit performance. The power harvester has been optimized to achieve maximum sensitivity by characterizing both the impedance transformation network and the rectifier circuit and choosing the optimum values for the circuit parameters. The measurement results show sensitivity of 14.1 dBm for dc output voltage of 1 V and the output current of 2 mum that corresponds to the output power of 2 muW.

Comprehensive Design of a Three-Phase Three-Switch Buck-Type PWM Rectifier

Abstract: A three-phase three-switch buck-type pulsewidth modulation rectifier is designed for telecom applications in this paper. The rectifier features a constant 400-V output voltage and 5-kW output power at the three-phase 400-V mains. The principle of operation and the calculation of the relative on-times of the power transistors are described. Based on analytical relationships the stresses of the active and passive components are determined and the accuracy of the given calculations is verified by digital simulations. Exemplarily, a 5-kW power converter is then designed based on the analytical expressions and on switching loss measurements from a hardware prototype constructed with insulated gate bipolar transistor/diode power modules. The loss distribution of the components, the total efficiency, and the junction temperatures of the semiconductors are then evaluated in dependency on the operating point. Finally, the trade-off between the selected switching frequency and the admissible power range for the realized design is shown and a total efficiency of 95.0% is measured on the hardware prototype, where an excellent agreement with the theoretically evaluated efficiency is shown

A Complete Harmonic Elimination Approach to DC Link Voltage Balancing for a Cascaded Multilevel Rectifier

Abstract: This paper presents a complete method that is used to balance dc link voltages in a cascaded H-Bridge (CHB) multilevel rectifier. Recently, such converters have been the subject of extensive research due to their suitability for high-power applications. One requirement in using a multilevel active rectifier at high levels of power is to limit the switching losses by reducing the switching frequency to a minimum. Another requirement for these converters is to ensure that individual dc link capacitor voltages for each cell of the converter are always balanced to ensure controllability and to limit stress on the converter cells. This paper presents a complete method in solving both of these problems using a selective-harmonic-elimination pulsewidth-modulation scheme. The scheme utilizes a simple controller to track each cell dc link capacitor voltage magnitude and accordingly biases the power flowing into each cell to ensure that the voltages across each cell capacitor converge. This is the case even when the loads attached to the individual cells are not balanced. The theory is supported by both simulated results from Saber and by experimental results from a seven-level CHB single-phase multilevel rectifier.

Theoretical analysis and optimal design of LLC resonant converter

Abstract: A LLC resonant topology is analyzed to derive efficiency and cost optimal design for wide input ranges and load variations In the LLC converter, a wide range of output power is controlled with only a narrow variation in operating frequency since this converter is capable of both step-up and step-down In addition, ZVS turn-on and ZCS turn-off of MOSFETs and diode rectifiers can be achieved over the entire operating range Finally, the inductance of a resonant tank in the primary side can be merged in the main power transformer by resonant inductance and the absence of the secondary filter inductor makes low voltage stress on secondary rectifier and cost-effective property DC characteristics and input-output response in frequency domain are obtained with the equivalent circuit derived by first harmonic approximation (FHA) method In addition, operational principles are explained to show the ZVS and ZCS conditions of primary switches and output diode rectifiers, respectively Efficiency and cost optimal design rules of the LLC resonant converter are derived by a primary resonant network, operating frequency, and dead time duration Proposed analysis and designation are proved by experimental results with a 400 W LLC resonant converter

Compensator Design and Stability Assessment for Fast Voltage Loops of Power Factor Correction Rectifiers

Abstract: This paper introduces a new method for stability analysis and design of fast voltage-loop compensators in rectifiers with power factor correction (PFC). The method has few constraints and can be used with various implementations of the fast voltage loop. It is based on utilization of circle criterion, which unifies frequency domain and nonlinear system analysis. A step-by-step procedure of stability assessment and compensator design is described and demonstrated on two controller implementations. In the first system, the voltage-loop dynamic response of an experimental 200-W digitally-controlled boost-based PFC is improved with a self-tuning comb filter. In the second implementation, it is shown how the circle criterion can be used to design a fast voltage loop for controllers with regulation band, i.e., ldquodead-zone,rdquo element for ripple elimination.

Methods and apparatus for a resonant converter

Abstract: Methods and apparatus for a dc-dc converter for operating at substantially fixed switching frequency, the converter including a rectifier, and a resonant inverter coupled to the rectifier, the resonant inverter including a switch and a reactive network having first, second, third and fourth energy storage elements, wherein an impedance magnitude at the output of the switch due to the reactive network has minima at dc and at a frequency near a second harmonic of the switching frequency.

Design and Analysis of Isolated ZVT Boost Converters for High-Efficiency and High-Step-Up Applications

Abstract: The fundamental limitations of the current topologies for isolated high step-up dc-dc conversion are summarized The primary-parallel-secondary-series structure is employed in this paper to handle the large input current, sustain the high output voltage and extend the voltage gain A novel active clamp boost converter with coupled-inductors is proposed for high step-up applications The third windings of the coupled-inductors have the function of voltage gain extension and the switch voltage stress reduction The active clamp circuit serves for the interleaved two phases, which reduces the circuit complexity Both the main and the auxiliary switches of the proposed converter are zero voltage transition performances during the whole switching transition Meanwhile, the leakage energy is recycled by the active clamp circuit The rectifier voltage stress is reduced by the primary-parallel-secondary-series structure The rectifier reverse-recovery problem is alleviated by the leakage inductance Experimental results for a 40-V-to-760-V converter verify the significant improvements in efficiency

Switching power supply

Abstract: A switching power supply capable of correcting a power factor without using a shunt resistor is provided. The switching power supply includes a rectifier for rectifying an AC power supply, boosting means including a power MOSFET for boosting an output of the rectifier, a smoothing capacitor for smoothing an output of the boosting means, voltage-dividing resistors for detecting a voltage between main terminals of the power MOSFET, a switch for selecting only the voltage by which the power MOSFET is in on-state from voltages detected by the voltage-dividing resistors, an amplifier for amplifying the voltage selected by the switch and outputting the same as a current corresponding value of a current flowing in the power MOSFET, voltage-dividing resistors for detecting the output voltage, and driving means which form a pulse signal based on the current corresponding value and the output voltage for driving the power MOSFET by the pulse signal.

Efficiency Comparison of Voltage-Source and Current-Source Drive Systems for Medium-Voltage Applications

Abstract: This paper calculates and compares the efficiency and loss distribution in the three most popular state-of-the-art types of large motor drive systems: 1) current-source drive with active front-end rectifier; 2) current-source drive with 18-pulse thyristor rectifier; and 3) three-level voltage-source drive with 12-pulse/24-pulse diode rectifier. For converter systems with efficiencies better than 90%, it is suggested to calculate or measure the losses of all the components separately and add them up to calculate the total efficiency. A simple and accurate method of calculating switching losses for a current-source and voltage-source converter is proposed. Through the calculation and simulation of each loss factor such as switching losses, conduction losses, and snubber and filter losses, the three-level voltage-source drive system has been found to have the highest efficiency of 98.77% under the rated load of 1.6 MW.

Space Vector Modulation for Vienna-Type Rectifiers Based on the Equivalence between Two- and Three-Level Converters: A Carrier-Based Implementation

Abstract: This paper presents the equivalence between two- and three-level converters for the Vienna rectifier, proposing a simple and fast space vector modulator built on this principle. The algorithm is further simplified by deriving its carrier-based equivalent implementation, which enables the midpoint voltage control by adjusting the ratio between redundant vectors, while also addressing the voltage-current polarity constraints of this non-regenerative three-level rectifier. The latter is achieved by employing a simple two-level overmodulation algorithm, which also extends the operating range of the Vienna rectifier if required. The proposed algorithm also complements previous carrier-based space vector modulators developed for the three- level neutral-point-clamped inverter, providing the midpoint balancing capability for these schemes. Experimental results obtained with a 2 kW 40 kHz 200 Vdc DSP/FPGA controlled Vienna rectifier prototype are presented for verification purposes.

Direct-coupled it load

Abstract: Apparatus and associated method and computer program products involve a highly efficient uninterruptible power distribution architecture to support modular processing units. As an illustrative example, a modular processing unit includes an integrated uninterruptible power system in which a PFC-boost AC-to-DC conversion occurs between the utility AC grid and the processing circuit (e.g., microprocessor) loads. In an illustrative data center facility, a power distribution architecture includes a modular array of rack-mountable processing units, each of which has processing circuitry to handle network-related processing tasks. Associated with each modular processing unit is an integrated uninterruptible power supply (UPS) to supply operating power to the network processing circuitry. Each UPS includes a battery selectively connectable across a DC bus, and a AC-to-DC rectifier that converts an AC input voltage to a single output voltage on the DC bus. The regulated DC bus voltage may be close to the battery's fully charged voltage.

A spiral-shaped harvester with an improved harvesting element and an adaptive storage circuit

Abstract: A piezoelectric energy harvester consists of a spiral-shaped piezoelectric bimorph to transfer mechanical energy into electric energy, an electrochemical battery to store the scavenged electric energy, and a rectifier together with a step-down dc-dc converter to connect the two components as an integrated system. A spiral-shaped harvesting structure is studied in this paper because it is very useful in the microminiaturization of advanced sensing technology. The aim of employing a step-down dc-dc converter in the storage circuit is to match the optimal output voltage of the piezoelectric bimorph with the battery voltage for efficient charging. In order to raise the output power density of a harvesting element, moreover, we apply a synchronized switch harvesting on inductor (SSHI) in parallel with the piezoelectric bimorph to artificially extend the closed-circuit interval of the rectifier. Numerical results show that the introduction of a dc-dc converter in the storage circuit or a SSHI in the harvesting structure can raise the charging efficiency several times higher than a harvester without a dc-dc converter or an SSHI

Improvement of Predictive Current Control Performance Using Online Parameter Estimation in Phase Controlled Rectifier

Abstract: In a phase controlled rectifier, the fastest response can be achieved by predictive current control without any overshoot. However, any error in the load parameters can cause steady state errors between a reference current and the feedback current because this current control scheme depends on the mathematical relationships between the output current, the firing angle, and the power source voltage. Thus, in the predictive current control, an accurate parameter is necessary for attaining a zero steady-state error. In this paper, the load resistance and inductance are estimated using the least square method of an online parameter calculation based on digitally sampled instantaneous voltage and currents. For the careful sampling of data and the reduction of the calculation time, a new timer-based gating algorithm is proposed and explained in detail. Using the proposed algorithm, the fastest current control performance in the transient state is obtained by the online correction of load parameters in various simulations and experimental results.

Systems and methods for improved motor drive power factor control

Abstract: Systems and methods are described for controlling power factor in motor drives having a switching rectifier providing a DC link current to an inverter in which the rectifier gain is increased to provide additional DC link current to correct the drive power factor based on current drawn by capacitors of the AC drive power input, and the inverter gain is decreased by introducing bypass states in the inverter switching control scheme or by reducing the motor flux to accommodate the increased DC link current.

Reduced Acoustic Noise Variable DC-Bus-Voltage-Based Sensorless Switched Reluctance Motor Drive for HVAC Applications

Abstract: In this paper, a control strategy for reduced acoustic noise and sensorless operation of a switched reluctance (SR) motor is proposed for heating, ventilation, and air conditioning (HVAC) application, where the magnitude of the dc-bus voltage is controlled as a function of speed and the motor is operated in a single-pulse mode for all speed range. The dc-bus voltage is controlled by incorporating a dc chopper between the three-phase line rectifier and a split dc-link capacitor-type four-switch power converter. Such controller reduces the acoustic noise, provides more accurate position estimation for sensorless operation, and improves the life expectancy of the motor. The algorithm is first simulated through MATLAB/SIMULINK and then tested on a four-phase 8/6-pole 4-kW SR motor. The test results of achieved acoustic noise and improved sensorless operation are presented. Through the proposed method, the acoustic noise is reduced by almost 15 dB compared to the conventional scheme at low-speed regime. The proposed method is intended to drive a fan type of load in HVAC applications, where the dynamic performance requirement is not a stringent criterion.

An AA-Sized Vibration-Based Microgenerator for Wireless Sensors

Abstract: This paper deals with the vibration-to-electrical transducer that has an M-size form factor and generates a DC voltage that can power off-the-shelf integrated circuits. Vibration-powered wireless sensors obtain power from machine vibrations, human movement, or other forms of motion. The feasibility of incorporating micro power transducers (MPTs) with a voltage multiplier and rectifier to make a micro power generator (MPG) is demonstrated, that has the same size and shape as an AA battery. The AA-sized module includes a voltage multiplier and a large capacitor to produce the DC output

Soft Switched Full Bridge DC–DC Converter With Reduced Circulating Loss and Filter Requirement

Abstract: A new soft switched full bridge converter with phase-shift control is proposed to reduce the circulating loss in primary and the voltage stress in secondary side. Using a coupled winding of the filter inductor, two auxiliary voltage sources are generated to reset the primary current at circulating interval. An auxiliary clamp diode is used to clamp the voltage spike across the rectifier diode, which releases the voltage stress of the rectifier diode. Therefore, low break down voltage diodes are utilized to reduce the conducting loss and the reverse recovery loss. Also, the filter requirements are lowered due to the auxiliary voltage sources. A prototype is built up to verify the theoretical analysis.

Evaluation of SiC JFETs for a Three-Phase Current-Source Rectifier with High Switching Frequency

Abstract: This paper presents the switching characterization of 1200 V, 5 A SiC JFET prototype devices for application in an AC three-phase current-source rectifier (CSR) with a switching frequency of 150 kHz. The result of device on-resistance is shown as a function of junction temperature. Using a simplified gate drive design, the switching characteristics of the SiC JFET are measured experimentally at voltage levels up to 600 V, current up to 5 A, junction temperature up to 200 °C, and varying gate resistance. From these measurements, the switching times and energies are calculated and plotted for various conditions. Finally, the application of the SiC JFET in the CSR is discussed, and conduction and switching losses are calculated. Results show that the SiC JFET provides low switching loss, even at high switching frequencies.