Full-bridge Type Research Articles

Associated power converters to the drive of a three-phase induction motor in a personal mobility electric vehicle

In this work it defines the analysis, design and construction of the associated power converters to the drive of a squirrel cage type three-phase induction motor. The final goal is to mount the mentioned motor with the control scheme in a personal mobility electric vehicle (PMEV); therefore, it will be necessary to power it with a battery pack, this creates the need for a current inversion stage, going from direct current (DC) to alternating current (AC). In order to solve this problem as from the power electronics point of view, to connect a high gain boost converter to the DC power supply (batteries) it is proposed, and then, can rise the output voltage of this stage, in order to supply the DC input voltage for a full-bridge type three-phase inverter. The necessary control scheme will be applied to the inverter to achieve that the motor speed follows a speed reference.

A Forward-Type Single-Stage Multi-Input Inverter With Series-Time-Overlapping Power Supply

A Forward type single-stage multi-input inverter with series-time-overlapping power supply is proposed. The circuit structure and topological family, energy management control strategy (EMCS), high frequency (HF) switching process analysis, the relationship between multiple duty cycles and power decoupling, common mode interference suppression between multiple inputs are fully studied. The circuit structure is composed of multi-input selection switches in series and an isolated bidirectional Forward type single input single output inverter. This topological family includes 6 circuits such as full-bridge type. A master-slave energy management SPWM compound control strategy with independent control of input source power based on input voltage feedforward and output voltage feedback is proposed. It realizes the energy management of the input source by controlling the instantaneous value of the output voltage and the output power ratio of the multiple inputs and achieves the smooth switching between the two power supply modes. The designed and developed 3kVA inverter prototype has excellent performances such as single-stage power conversion, HF electrical isolation, high conversion efficiency, small size and weight, wide duty cycle adjustment range, high output waveform quality, and strong load adaptability.

Unified Fast-Dynamic Direct-Current Control Scheme for Intermediary Inductive AC-Link Isolated DC-DC Converters

The isolated dc-dc converters with middle inductive AC links dc-dc converter have been extensively studied in modern energy conversion applications for safety and reliability, especially those featuring intermediary inductive ac-link (I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL) configurations such as full-bridge dc-dc converter and dual-active-bridge (DAB). However, up to now, the dynamic equivalence in these I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL type converters has not been systematically revealed. To fill such a gap, in this paper, the existing I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL isolated dc-dc converters are reviewed thoroughly, including unidirectional type and bidirectional type. Then, the general current transferred features of these two groups are analyzed, respectively, and the transferred current during the transient process is just influenced by the middle inductance little. So, the I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL isolated dc-dc converter can be regarded as the first-order converter. Based on the discovered general characteristic, a unified fast-dynamic direct-current (FDDC) control scheme is proposed for improving the dynamic performance of these I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL isolated dc-dc converters. Such a scheme can also facilitate the uniform control design for existing or emerging new topologies with the same electrical equivalence. Moreover, the specialized design principles of the PI parameters in the unified FDDC control method are also presented. Finally, to verify the universality and feasibility of the proposed general FDDC control strategy, both simulation and experiment results are presented with demonstration examples, e.g., full-bridge type, DAB-type, and the three-phase DAB type dc-dc converters.

Design of a full-bridge type fault current limiter

Compared to AC system, DC power system is more likely to be damaged by short current, because in DC system the fault current increases faster and doesn’t have zero crossing point. The DC current limiter (FCL) can limit the rise of the current, thus it is efficient to use FCL to improve the reliability of the power system. Based on the previous research, we proposed an improved topology, established its mathematical model and analyzed its working processes. Besides, parameter design methods of solid-state DC current limiter are proposed by combining modeling and image analysis. And the control strategy of DC transformer short circuit fault crossing and recovery is put forward. Simulation and experiment results proved the effectiveness of topology and control strategy we proposed.

Analysis on topology derivation of single-phase transformerless photovoltaic grid-connect inverters

Aiming at the leakage current problem of single-phase transformerless photovoltaic(PV) grid-connected inverters, the recent proposed topologies are classified and reviewed. These topologies are divided into half-bridge type and full-bridge type. The topology characteristics of transformerless PV inverter are analyzed. This paper presents some of transformerless PV inverter topologies and discusses the evolution laws among various topologies to clarify the interrelationship between them. Furthermore, according to the evolution laws, a new topology is proposed. Finally, Simulations and experiments compare leakage current suppression capability of the proposed topology, H5 topology and HERIC topology.

A feasibility study of full-bridge type superconducting fault current controller on electric machine power stability

Recently, because of the advent of Smart Grid and integration of distributed generations, electrical power grids are facing uncountable challenges. Increase of fault current is one of such serious challenges and there are some fault current limiters (FCLs) that can limit the fault current. Existing grid protection FCLs, however, simply limit the fault current passively and can allow the existing protection coordination schemes to fail. This phenomenon leads to catastrophic failure in the complex system and may cause unpredictable power grid operation. Unlike a FCL, a superconducting fault current controller (SFCC) employs a full-bridge thyristor rectifier, a high temperature superconducting (HTS) DC reactor, and an embedded control unit to maintain the fault current level at a proper value by adjusting the phase angle of thyristors. This paper contains experimental and numerical analysis to design and fabricate a SFCC system for protection and stability improvement in power grids. At first, fundamental characteristics of a SFCC system were introduced. System circuit diagram and operational principles were proposed. Secondly, the developed small-scale SFCC system was introduced and verified. A 40 Vrms/30 Arms class prototype SFCC employing HTS DC reactor was fabricated and short circuit tests that simulate various fault conditions were implemented to verify the control performance of the fault current. Finally, the practical feasibility of application of the SFCC system to the power system was studied. The problems caused by three-phase faults from the power grid were surveyed and transient stability analysis of the power system was conducted by simulations. From the experimental and simulation results, we can verify the feasibility of the SFCC in power system.

フルブリッジ型双方向DC/DCコンバータの2次側短絡によるサージ電圧抑制

The full-bridge type bidirectional DC/DC converter is considered to be a promising topology for large capacity DC/DC conversion. Bidirectional DC/DC converter have two operation modes : Current-Mode and Voltage-Mode. It is well known that large surge voltage is generated at switching devices with current mode operation. The main factor of surge voltage is the leakage inductance of the transformer. The purpose of the study is the suppression of the surge voltage caused by the leakage inductance. In this paper we propose a novel control strategy which reduce the surge voltage of switching devices at current mode operation. Finally, experimental results of laboratory model which applied the new control strategy are presented, in which the reduction of surge voltage is realized.

High Power Full-Bridge DC-DC Converter using a Center-Tapped Transformer and a Full-Wave Type Rectifier

This paper proposes a high power full-bridge DC-DC converter, using a center-tapped transformer and a full-wave type rectifier. The proposed converter realizes unipolar primary voltage switching, using the unipolar pulse-width modulation (PWM) technique. Also, the proposed converter reduces the freewheeling conduction loss, using the unipolar PWM technique and a resonant circuit, composed of a clamp capacitor and resonant inductor in the primary, and thus achieves high efficiency. However, because the proposed converter uses only a full-bridge circuit, center-tapped transformer, and full-wave type rectifier, the structure of the proposed converter is simple. In this paper, the operational principle of the proposed converter is described in detail, and a design example of a proposed converter prototype is shown. Finally, experimental results of the prototype are shown, to verify the feasibility of the proposed converter.

Improvement of Stability for NO Removal in Multipoint Barrier Discharge Reactor by Pulse Applied Voltage

AbstractImprovement of stability for NO removal in dielectric barrier discharge (DBD) reactor by pulse applied voltage is described in this paper. Two different types of power supply are used to drive the DBD reactor. The ac type power supply produces a sinusoidal waveform at 10 kV in amplitude and 10 kHz in frequency. The pulse voltage of 10 kV is generated by a full-bridge type pulse modulator using insulated gate bipolar transistor (IGBT) switches. A duty factor of the pulse voltage is controlled in the range from 10 to 80% with a gate signal of the IGBT switches. A multipoint electrode is used in the DBD reactor for low voltage drive. NO gas is diluted with nitrogen and oxygen gas mixture (N

Millimeter-Scale Piezoresistive Cantilevers for Accurate Force Measurements at the Nano-Newton Level

This paper reports a development of millimeter-scale cantilevers equipped with piezoresistive deflection sensing metrology as a force sensor at the micro- and nano-Newton level. The cantilevers was designed and fabricated to minimize the error during the force transfer or calibration, so that they have full-bridge type piezoresistors, a large length and width and reference marks to facilitate the positioning of probes or tips onto the piezoresistive cantilevers. Their 6 mm-long and 0.4 mm-wide dimensions can reduce the error due to incomplete contact (or loading) position. The reference marks on the cantilever can give you a range of stiffness and force sensitivity with a single piezoresistive cantilever. The stiffness can vary from 25 N m−1 at the first mark to 0.04 N m−1 at the last. The full-bridge piezoresistors give an electrical signal proportional to the applied force with superior temperature independency. The fabricated piezoresistive cantilevers were calibrated with the KRISS nano force calibrator (NFC). The results showed that the stiffness and the force sensitivity at the last mark was determined to be 0.0502 N m−1 and 0.357 (mV/V) μN−1, respectively. The performances were tested by calibrating stiffness of commercial cantilevers using the cantilever-on-cantilever method with a fabricated cantilever and comparing calibration results with stiffness obtained from calibration using the NFC. Two results match to each other within approximately 10 % discrepancy.

Sand Shearing Peculiarities Using Direct Shear Device

An experimental investigation of the shearing conditions and their influence to the strength properties of Klaipėda sand by the universal shear device is presented. The shear tests for the loose and dense soils were realized for constant vertical stress (q = const.) and for constant sample volume (h = const.), respectively. Loading was supplied on the top of the sample. The testing conditions realized the cases of the constant and variable gap between upper and lower shearing ring. The stability of the gap between the upper and the lower shearing rings and that of the vertical load indicator of compression were measured during the tests. The measurements of the gap between the upper and the lower shearing rings resulted that it is not constant during the tests. The compression measurement tests of vertical load indicator it was found that full bridge type indicators are not proper for tests because of their deformability. The angle of the internal friction φ and the cohesion c depends on: density of soil; testing method; gap behavior factor: is it fixed or not.

Novel SRM Drive Systems Using Variable DC-Link Voltage

This paper proposes two SRM driving systems using a variable dc-link voltage controlled by a single-phase inverter. Two SRM converter topologies of a half bridge type and a full bridge type are proposed according to the power circuits of an inverter. The phase current can be controlled by means of a PWM controller at the inverter, and the turn-on/off angle at the phase switches can be controlled by a position sensor at the converter in the drive system. The inverter acts as a peak-current limiter if the transient current exceeds its maximum value. SRMs using the proposed topologies maintain high efficiency due to energy regeneration after the turn-off of power switches. The operational modes of the proposed topologies are verified by simulation and experimental results.

Generation of Multiphase Pulsed Voltages for Transdermal Drug Delivery

This paper first reviews the mechanism of transdermal drug delivery (TDD) and then presents the method for generating multiphase pulsed voltages (MPPVs) for TDD applications. In TDD applications, it offers many potential advantages over conventional methods, such as oral and injection treatments, and it avoids drug degradation through the gastrointestinal tract and liver. Due to the energy stored in an equivalent capacitor of human skin which is about 30% of the total energy consumption, a full-bridge type of converter is designed to recover this energy, and additionally, it is equipped with a soft-switching cell to achieve a zero-voltage switching or a zero-current switching, improving the efficiency of about 20%. The overall system needs only a set of soft-switching cells to achieve a soft-switching feature even though it can generate sets of pulsed voltages, reducing size and cost significantly. Moreover, the MPPVs are introduced to further improve the effectiveness of drug delivery. Experimental results from the TDD application with a 150-V output voltage and a 110-W peak power have demonstrated the feasibility of the proposed generator.

Tapped-inductor filter assisted soft-switching PWM DC-DC power converter

A novel high-frequency transformer linked full-bridge type soft-switching phase-shift pulsewidth modulated (PWM) controlled dc-dc power converter is presented, which can be used as a power conditioner for small-scale photovoltaic and fuel cell power generation systems as well as isolated boost dc-dc power converter for automotive ac power supply. In these applications with low-voltage large-current sources, the full-bridge circuit is the most attractive topology due to the possibility of using low-voltage high-performance metal-oxide-semiconductor field-effect transistor (MOSFET) and achieving high efficiency of the dc-dc power converter. A tapped-inductor filter including the freewheeling diode is newly implemented in the output stage of the full-bridge phase-shift PWM dc-dc converter to achieve soft-switching operation for the wide load variation range. Moreover, in the proposed converter circuit, the circulating current is effectively minimized without using additional resonant circuit and auxiliary power switching devices. The practical effectiveness of the proposed soft-switching dc-dc power converter was verified in laboratory level experiment with 1 kW 100 kHz breadboard setup using power MOSFETs. Actual efficiency of 94-97% was obtained for the wide duty cycle and load variation ranges.

Pulse Density Modulated High Frequency Inverter for Silent Discharge Excimer Lamp Drive

This paper presents a single inductor snubber-assisted full bridge type high frequency series resonant inverter using MOSFETs for the silent discharge type excimer lamp drive, which can achieve ZCS commutation. Its operating principle is presented, together with its output power regulation characteristicsbased on pulse density modulation.

A Three-Phase AC-DC Converter using World-Wide PFC Circuit and Phase Shift Controlled DC-DC Converters

This paper describes a three-phase AC-DC converter using world-wide PFC (Power Factor Correction) circuit and soft switching full bridge type DC-DC converters. The feature of our new PFC circuit is unity power factor and low harmonics distortion of the input currents, high efficiency and low impressed voltage on the semiconductors. Furthermore, we indicate a method to improve the efficiency and the output voltage ripple at the switching transient of the DC-DC converter using phase shift control. According to the experimental results, the PFC circuit can be applied the semiconductors with the rating voltage 600V at the input voltage AC200V or AC400V. In addition, the input power factor, the efficiency, and the output voltage ripple of the AC-DC converter are good value.

Full-bridge capacitive extensometer

Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge circuit, which is a useful means for employing synchronous detection to improve signal to noise ratios. Unlike previous differential capacitive dilatometers which used only two active capacitors, the present sensor is a full-bridge type, which is well suited to measuring low-level thermal expansions. This analog sensor is capable of 0.1 μm resolution anywhere within a range of several centimeters, with a linearity of 0.1%. Its user friendly output can be put on a strip chart recorder or directed to a computer for sophisticated data analysis.