An economical four-quadrant GTO converter and its application to DCdrives

A four-quadrant gate turn-off (GTO) power converter employing a single six-GTO bridge and four thyristors as reversing switches is described. Such a four-quadrant converter is economical compared to a dual-converter employing two bridges, each with six GTOs. A four-quadrant DC motor drive employing the proposed converter and closed-loop speed control with an inner current control loop is also presented. The controllers are designed using symmetric optimization. Experimental results with a 3 HP DC motor are given for steady-state and transient responses of the drive. A comparative study of the present four-quadrant drive and the one reported earlier is also presented     

A NOVEL PASSIVE DUAL ENERGY RECOVERY SNUBBER FOR HIGH POWER GTO CONVERTERS

A novel passive dual energy recovery snubber circuit is presented where energy trapped in the snubber inductor and capacitor is recovered into the both DC rail and load, without any active devices or resistors. The maximum over-shoot voltage on the switch is fixed, peak switch current is low, circuit reset is fast and the operational range of load current is wide. This circuit is suitable for use in high frequency, single ended power gate turn-off (GTO) thyrister choppers. Main design equations, some simulations and practical results are included.     

A compact DC-to-DC power converter for distributed power processing

The authors present a compact (55-W/in³), efficient (86% power train), 1-MHz switch-mode, DC-to-DC power converter contained in a 2-in by 2-in by 0.25-in, 1-in³ package. They describe the interleaved forward topology, steady-state analysis, switch transitions, capacitor substrate, planar printed-wiring-board transformer, packaging, electrical performance, power loss analysis, thermal analysis, reliability, and efficiency and power density improvements     

Instantaneous control method with a GTO converter for active andreactive powers in superconducting magnetic energy storage

A new type of GPG (gate pulse generator) is presented to give GTO power converters quick response firing angle control and PWM control functions. Using the GPG, an instantaneous control method of active and reactive powers for an SMES (superconducting magnetic energy storage) employing one GTO converter is studied     

Low-harmonic distortion in single-ended and push-pull class E power amplifier by using slotted microstrip lines

In this work, a very low-harmonic distortion with high power-added efficiency (PAE) power amplifier (PA) with slotted microstrip lines is reported. The circuit is a push-pull class E amplifier, terminated with defected structures to improve the spectrum purity and efficiency. The relationship of the second and third harmonic to the fundamental is 70 and 54 dBc, respectively. The amplifier is developed with HBT medium power transistors. The circuit works at 1.8 GHz obtaining a PAE close to 60%, delivering an output power of 24 dBm with a power gain of 13.3 dB.     

A nonconventional power converter for plasma stabilization

The authors present the design and control of a nonconventional converter with a peak power of 3.6 MVA and a bandwidth ranging from DC values up to 10 kHz for nuclear-fusion experiments. The novel control technique is based on a comparison between the current reference and the load current, through a hysteresis comparator system. The required voltage waveforms have been obtained in two specified frequency ranges, with a strictly unified control over the whole bandwidth range. The conditions on the maximum phase shift and the maximum switching frequency required have all been fulfilled. Excellent results obtained by digital simulation confirm the validity of the proposed control scheme. The converter described here has been studied and designed for an experiment that has recently been proposed within the framework of the JET (Joint European Torus) project     

GTO

可关断晶闸管（GTO（Gate Turn-Off Thyristor）是具备开关功能的电力半导体器件。与一般晶闸管相比,其优点是可不必为关断而设置换流电路。主要特点为：当栅极加负向触发信号时晶闸管能自行关断。普通晶闸管（SGR）靠栅极正信号触发之后,撤掉信号亦能维持通态。欲使之关断,必须切断电源,使正向电流低于维持电流IH,或施以反向电压强近关断。     

Extended fundamental frequency analysis of the LCC resonant converter

Fundamental frequency techniques are used to analyze the series-parallel resonant converter under heavy load conditions, both with a continuous, but distorted parallel capacitor voltage waveform, and with a discontinuous capacitor voltage waveform. The analysis is validated with results from an experimental prototype. The application of the technique to the parallel-loaded L-C resonant converter is also considered.     

Design of multiple-input power converter for hybrid vehicles

This paper deals with designing and sizing of a multiple-input power electronic converter (MIPEC) to be used in an electric vehicle propulsion system that includes a fuel cell (FC) generator and a combined storage unit. The combined storage unit is composed by an ultracapacitors tank (UC) and a battery unit (BU). MIPEC is responsible for power-flow management on-board the vehicle for each mode of operation. Specifications for MIPEC designing come out from many considerations concerning traction drive and reference driving cycle, on-board power source and storage unit characteristics. However, to date sizing and configuration of both storage units and on-board generators are directly related to traction drive and driving profile (i.e., vehicle performances and characteristics) and no relation with power electronic interface is considered during preliminary design. Then, power electronic interface is selected in order to fit traction drive requirements with power source and storage unit characteristics; as a consequence converter mode of operation lacks of optimization, as well dynamic behavior and efficiency cannot be maximized. In this paper, MIPEC design and power source and storage unit selection are achieved at the same project stage according to traction drive requirements. Experimental results on 60-kW power electronic interface are presented.     

A versatile power converter for high-frequency link systems

A single-phase high-frequency link appears to be an attractive alternative to the DC link commonly used in power conversion systems. The authors propose a power converter suitable for one-step conversion of the single-phase high-frequency link voltage to the three-phase low-frequency voltages typically required for interfacing with system sources and loads. The converter utilizes zero voltage switching principles to minimize switching losses and uses an easy-to-implement technique of pulse density modulation for the control of the amplitude, frequency, and waveshape of the synthesized low-frequency signals. Adaptation of the proposed topology for power conversion to single-phase AC and DC voltage or current outputs is shown to be straightforward. The feasibility of the proposed power circuit and the control technique have been experimentally verified     

ZVT-PWM boost converter for unity power factor applications

A new single-phase ZVT-PWM boost converter with an active snubber is proposed to achieve unity power factor operations for a wide load range. The unique location of the resonant inductor and capacitor ensures that low switching stress and commutation losses are obtained in the converter. The proposed converter is suitable for high power factor correctors     

Control and performance of a self-commutated GTO converter operating in parallel with line-commutated thyristor converters

Recently, static var generators (SVGs) or static synchronous compensators based on self-commutated converters have been put into practical use for the purpose of compensation for reactive power, power swings damping, and/or voltage control in power systems. The SVGs have also been applied to reduce voltage fluctuations appearing at high-speed train substations. When parallel resonance occurs between passive filters installed at a point of common coupling (PCC) and the power-system impedance existing upstream of the PCC, voltage/current harmonics are significantly amplified in the power system. This paper describes the control and performance for a self-commutated gate-turn-off (GTO) converter operating in parallel with conventional line-commutated thyristor converters. This hybrid power conversion system rated at more than dozens of MVA has an inductive load at the dc side. A bank of passive filters is connected not only for harmonic compensation of the line-commutated converters, but also as a constant leading reactive-power source. The GTO converter can control either leading or lagging reactive power so as to achieve unity power factor operation. In addition, it has the capability of damping out parallel resonance between the passive filters and the power-system impedance. This paper confirms the viability and effectiveness of the hybrid system by means of theory and computer simulation.     

智能野战万用电源变换器

介绍一种基于单片机的智能野战万用电源转换器的原理.该电源转换器能适应多种环境电源的输入,而输出稳定可靠的交流220V电压.     

新型开关电源控制方法研究

VRM作为电压调节模块具有快速的动态响应性能,但传统的V2C控制方法有其固有的缺点。为了提高VRM的动态性能和鲁棒性,在此分析了传统控制方式的固有缺陷,并以传统Buck变换器为平台提出新的双闭环模糊PID控制方法,最终希望提高VRM的抗干扰性。提出的控制方法通过引入非线性的模糊PID控制器闭环稳定输出电压并引入PID负载电流控制器加快动态响应,同时在参数设置中尝试兼顾稳定性、快速动态响应性能和鲁棒性。最后通过仿真得到可以稳定输出的变换器电路并证明了该新型控制器具有良好的动态性能和控制精度。     

An integrated flyback converter for DC uninterruptible power supply

An integrated flyback power converter performing the combined functions of uninterruptible power supply (UPS) and switch-mode power supply (SMPS) is presented. This power converter has a high voltage main power input and a low voltage backup battery input. DC output is obtained from the main input via a flyback power converter during normal operation and from the backup battery via another flyback power converter when input power fails. High conversion efficiency is achieved in normal, backup, and charging modes as there is only a single DC-DC conversion in each mode. The power converter circuit is very simple, with two switching transistors, a relay for mode switching, and a single magnetic structure only. This new design offers substantial improvement in efficiency, size, and cost over the conventional cascade of UPS and SMPS due to single voltage conversion, high frequency switching, and removal of design redundancy. The operation, design, analysis, and experimental results of the power converter are presented     

A bidirectional DC-DC converter topology for low power application

This paper presents a bidirectional DC-DC converter for use in low power applications. The proposed topology is based on a half-bridge on the primary and a current-fed push-pull on the secondary side of a high frequency isolation transformer. Achieving bidirectional flow of power using the same power components provides a simple, efficient and galvanically isolated topology that is specially attractive for use in battery charge/discharge circuits in DC UPS. The DC mains (provided by the AC mains), when presented, powers the down stream load converters and the bidirectional converter which essentially operates in the buck mode to charge the battery to a nominal value of 48 V. On failure of the DC mains (derived from the AC mains), the converter operation is comparable to that of a boost and the battery regulates the bus voltage and thereby provides power to the downstream converters. Small signal and steady state analyses are presented for this specific application. The design of a laboratory prototype is included. Experimental results from the prototype, under different operating conditions, validate and evaluate the proposed topology. An efficiency of 86.6% is achieved in the battery charging mode and 90% when the battery provides load power. The converter exhibits good transient response under load variations and switchover from one mode of operation to another     

Improved small-signal analysis for the phase-shifted PWM power converter

A closed form cycle by cycle analysis forms the basis for a new zero-voltage switching (ZVS) phase-shifted PWM (PSPWM) full bridge power converter small-signal model. The paper derives the small-signal response equations. The PSPWM converter has an implicit "slew interval," making the converter dynamics difficult to analyze using traditional averaging techniques. The converter control to output transfer function under continuous conduction mode operation and using voltage-mode control does not exhibit a second order pole associated with the output L-C filter, making it different from a conventional PWM converter. This new PSPWM converter model shows that the output L-C filter is separated into two real poles, with one pole held at constant frequency independent of operating conditions. A characteristic pole depends only upon the converter switching frequency and inductor values. This characteristic pole is fundamental to understanding the PSPWM converter natural and forced responses. The new small-signal model is shown to be in excellent agreement with experimental results.     

A low power time-to-digital converter for all-digital phase-locked loop

Time-to-Digital Converter (TDC) is a key block used as the phase/frequency detector in an All-Digital Phase-Locked Loop (ADPLL). Usually, it occupies a large proportion of ADPLL’s total power consumption up to about 30% to 40%. In this paper, the detailed power consumption of different components in the TDC is analyzed. A Power Management Block (PMB) is presented for the TDC to reduce its power consumption. A 24-bits TDC core with the proposed PMB is implemented in HJTC 0.18 μm CMOS technology. Simulation results show that up to 84% power reduction is achieved using our proposed technique.