同步整流驱动电路的种类

驱动同步整流管的方法可分为两种：第一种是外加控制驱动电路。这种方法驱动波形质量高，但增加了电路的复杂性和成本，一般很少采用。第二种是自驱动同步整流。一种简单的自驱动同步整流电路是在主变压器上加两个辅助绕组，直接获得驱动信号。另一种更简单经济的办法是直接从变压器副边主电路获得驱动信号。     

具有同步触发功能的大功率制动单元

大功率制动单元主要是基于降压斩波电路专用的功率器件来实现的,控制电路采用滞环控制和PWM驱动信号,通过自适应主从控制和同步触发功能来实现多台大功率制动单元并联工作来提高制动功率。     

三相混合式步进电动机斩波驱动方式的实现

在分析反应式和混合式步进电动机不同驱动特点的基础上，提出了三相混合式步进电动机的斩波驱动方式。针对具有上、下桥臂的逆变器，论述绕组电流的检测和转换。为提高驱动器的运行可靠性，设计了功率器件的保护电路。     

履带车辆电传动系统动力控制与性能仿真

电动车上驱动用的永磁同步电动机一般采用基速以下恒转矩、基速以上恒功率的控制方法。本文则用功率反馈(观测)方式完成电传动系统后功率链的动力控制,并通过试验说明它的正确性。在此基础上,进行绕组切换,即利用变结构进行扩速,研究并选定了绕组切换形式和对应的转速区域。最后给出了部分总体性能仿真结果,同时进行了分析。     

直流变频空调工作原理与维修（一）

一、直流变频空调的基本工作原理 直流变频空调控制器的原理框图如图1所示,主要由整流器、滤波器、功率逆变器、位置检测等电路组成。AC220V工频交流电经EMI电路后经整流电路转换为310V直流电源送到驱动模块。室外机的微处理器对各取样点送来的信号进行分析处理,并经内部波形产生新的控制信号,再经驱动放大去控制驱动模块,每次导通两只功率晶体管,给压缩机两相线圈通以直流电,驱动转子运转,另一相线圈不通电,但有感应电压,根据感应电压的大小可以判断出转子的位置,进而控制绕组通电顺序。     

单相电容同步反应式电动机的分析和计算

在需要恒速传动的小功率驱动系统中,常采用单相电容同步反应式电动机。它的转子可采用一般整体式凸极转子或分段式转子[文1],转子上都装有鼠笼式绕组;它的定子如同单相电容异步电动机,即主绕组A两端直接与单相电源相接,副绕组B两端串入分相电容C后再与单相电源相接,如图1所示。下面分别对它同步和起动运行时的情况进行分析。     

高速磁隔离驱动的同步脉冲群调制解调方法

高速磁隔离驱动电路的信号调制解调,一般采用正负单脉冲调制解调,解调电路一旦受到干扰翻转,则在下一个脉冲到来之前无法恢复正常,进而造成驱动故障.提出一种同步脉冲群调制解调电路,以提高驱动电路抗干扰误触发的能力,同时满足用于太阳电池最大功率跟踪等占空比变化较大的宽范围PWM信号传输.对电路的工作原理和参数设计进行了详细分析...     

桥式拓扑结构功率MOSFET驱动电路设计

针对桥式拓扑功率MOSFET因栅极驱动信号振荡产生的桥臂直通问题,给出了计及各寄生参数的驱动电路等效模型,对栅极驱动信号振荡的机理进行了深入研究,分析了驱动电路各参数与振荡的关系,并以此为依据对驱动电路进行参数优化设计,给出了实验波形.理论分析和实验结果表明,改进后的驱动电路成功地解决了驱动信号的振荡问题,从而保证了功率MOSFET能够安全、可靠地运行.     

0.75kW开关磁阻电机功率驱动电路设计

通过对开关磁阻电机驱动系统的研究,根据开关磁阻电动机伺服控制策略的要求,为四相(8/6极)、750W开关磁阻电动机设计一种适合的功率驱动电路,其目的可以快速而精确地控制相绕组的电流,能将绕组上的能量部分回馈给电源,同时满足一定转速范围,具有较高运行效率的要求.     

信号不对称对二相四绕组小功率无刷直流电动机稳态特性的影响

建立了二相四绕组单极性驱动小功率无刷直流电动机在控制信号不对称时的数学模型,研究了控制信号不对称对运行特性的影响。     

Soft switching DC/DC converter with high voltage gain and less current ripple

A new soft switching three‐level converter with two DC/DC circuits in the primary side and current double rectifiers in the secondary side is presented to realize the zero‐voltage switching operation, reduce the transformer secondary winding turns and the output current ripple, and lessen the voltage rating of rectifier diodes. Two DC/DC pulse‐width modulation circuits sharing same power switches with interleaved half switching cycle are adopted in the proposed converter to reduce the current rating of transformer primary windings. Two inductors and four diodes are adopted in the secondary side to achieve current double rectifier, reduce output ripple current, and decrease the transformer secondary winding turns. Based on the pulse‐width modulation scheme, the power switchers can be turned on at zero‐voltage switching operation. Laboratory experiments with a 1.44 kW prototype are provided to verify the theoretical analysis. Copyright © 2016 John Wiley & Sons, Ltd.     

Implementation of an interleaved pulse‐width modulation converter for renewable energy conversion

This paper presents an interleaved soft switching converter to achieve the features of zero voltage switching (ZVS) turn‐on for power switches, zero current switching turn‐off for rectifier diodes at full load, less transformer secondary winding with full‐wave diode rectifier topology, and balance primary currents with series connection of the transformer secondary windings. Two circuit modules are adopted in the proposed circuit, and they are operated with an interleaved pulse‐width modulation. Thus, ripple currents at the input and output sides are reduced. In each module, two ZVS converters using the same switches are operated with interleaved half switching cycle. The secondary windings of transformers are connected in series in order to ensure that the primary side currents are balanced. The full‐wave diode rectifier topology is used on the output side such that the voltage stress of rectifier diodes equals output voltage, rather than being two times the output voltage as in a conventional center‐tapped rectifier topology. Laboratory experiments with a 1000‐W prototype are provided to describe the effectiveness of the proposed converter. Copyright © 2011 John Wiley & Sons, Ltd.     

An improved full-bridge zero-voltage switching PWM converter usinga two-inductor rectifier

An improved full-bridge ZVS PWM power convertor using a two-inductor rectifier DC/DC power converter is presented in this paper. For this improved topology, the main devices are switched under zero-voltage (ZVS) conditions using the energy stored in the secondary filter inductors. In addition, it utilizes the low leakage inductance of a coaxial winding transformer to reset the currents in the rectifier diodes and eliminate the secondary voltage spike. The two-inductor rectifier has only one diode conduction drop in addition to frequency doubling in the output capacitor. The secondary filter size in the proposed topology is rather small. The advantages of the new topology include a wide load range with ZVS, no lost duty cycle due to diode recovery, no secondary voltage spikes, in addition to high power density and high efficiency     

Analysis of the ZVS two‐switch forward converter with synchronous current doubler rectifier

A soft switching two‐switch forward converter is presented to achieve zero voltage switching (ZVS) turn‐on of switching devices. In the adopted converter, a buck‐boost type of active clamp is connected in parallel with the primary winding of transformer. The energy stored in the transformer leakage inductance and magnetizing inductance can be recovered so that the peak voltage stress of switching devices is limited. The resonance between the transient interval of two main and auxiliary switches is used to achieve ZVS turn‐on of all switches. The current doubler synchronous rectifier is used in the secondary side of transformer for reducing the root mean square value of output inductor current, transformer secondary winding current and output voltage ripple by cancelling the current ripple of two output inductors. First, the circuit configuration and the principles of operation are analyzed in detail. The steady‐state analysis and design consideration are also presented. Finally, experimental results with a laboratory prototype based on a 380 V input and 12 V/30 A output were provided to verify the effectiveness of the proposed converter. Copyright © 2007 John Wiley & Sons, Ltd.     

电流耦合型高压开关电源

高压开关变压器和整流器是高压开关电源的设计难点,现提出一种电流耦合型高压开关电源方案,其特点是由变压器和整流器一起构成高压变压整流组件.变压器的初、次级采用了全串联结构,使变压器的铁心、次级绕组和整流器均浮动在高电位;初级绕组浮动住低电位,较好地解决了高压绝缘等问题.采用这种设计方法的高压开关电源实现了模块化、组合化,可组合出各利电压和功率量级的全开关高压电源,有着广泛的应用前景.为验证该方案的正确性,给出了30kV/50kW的电流耦合型高压开关电源的实验结果.     

一种新型的永磁同步风力发电机并网系统

提出一种基于固态变压器的永磁同步风力发电机并网系统。在并网变流器中加入高频变压器,实现整流和逆变部分的电气隔离,高压侧变流器的输出电压达到10 kV, 从而减小了并网电流。在直流侧增加超级电容储能装置,使风电机组具备较强的低电压穿越能力。对系统的关键控制部分进行分析设计,建立了系统仿真模型。研究结果表明,所设计的新型风电并网系统能够明显减小并网冲击电流,并具有很强的低电压穿越能力,是一种有效的永磁同步风力发电机并网方法。     

基于自耦补偿与谐波屏蔽换流变压器的直流输电系统仿真研究

为揭示自耦补偿与谐波屏蔽(新型)换流变压器电磁暂态瞬变过程,模拟直流输电系统中新型换流变压器网侧与阀侧端口电压、电流的输入、输出特性以及交直流之间的相互 作用,利用仿真软件Matlab分别建立了用于6脉动与12脉动直流输电系统的新型换流变压器仿真模型,并将其应用到直流输电系统动态仿真中。仿真结果表明：新型换流变压器取代传统换流变压器在一定程度上优化了直流输电系统的结构,通过对变压器第三绕组的零阻抗设计及绕组抽头处滤波器参数的合理配置,既能降低换流变压器网侧谐波含量、有效减少谐波与无功对换流变压器的损耗,又改善了换流变压器阀侧的线电压与相电流,有利于换流器可靠换相与正常运行。     

特高压直流输电系统换流站故障过电压研究

±800 kV特高压直流输电系统换流站内电容性和电感性组件较多,在发生短路故障时容易引起过电压现象。研究各种操作和故障情况下过电压的特性,保证系统的安全稳定运行非常重要。利用PSCAD仿真软件建立了±800 kV云南—广东特高压直流输电工程的模型,在换流站内选取了换流阀阀顶对中性母线短路故障和换流变压器阀侧单相接地两种典型故障工况进行了研究。结果表明阀顶对中性母线故障时非故障极线路过电压水平较高,在上组四个换流变压器阀侧绕组中高压端Y/Y绕组端子处单相接地时的过电压水平最高。     

800kV浙西特高压直流换流站暂态过电压研究

基于溪洛渡—浙西800 kV特高压直流输电工程,对浙西换流站的暂态过电压和各避雷器的负载进行详细仿真计算分析。在交流侧选取了交流母线三相接地、交流相间操作冲击和失交流电源3种典型故障工况;直流侧选取了最高端换流变Y/Y绕组阀侧单相接地、低压端换流变Y/Y绕组阀侧单相接地和全电压启动3种典型故障工况进行研究。分析结果表明:失交流电源是交流侧的最严酷工况,交流母线过电压771 kV,通过交流母线避雷器A的最大电流0.14 kA,最大能量2.07 MJ;最高端换流变Y/Y阀侧单相接地在换流阀两端产生过电压375 kV,通过阀避雷器V1最大电流2.32 kA,最大能量6.73 MJ;低压端换流变Y/Y阀侧单相接地,阀避雷器V3通过最大电流1.04 kA,最大能量2.84 MJ;全电压起动在直流极母线上产生1 330 kV的过电压,避雷器DB通过最大电流0.56 kA,最大能量4.35 MJ。     

A modular power electronic transformer based on a cascaded H-bridge multilevel converter

In this paper a modular power electronic transformer (PET) for feeding critical loads is presented. The PE-based transformer is a multi-cellular step-down converter that can directly connect to medium voltage levels on the primary side and provide a low voltage, highly stable interface for consumer applications. The presented structure consists of three stages: a cascaded H-bridge (CHB) rectifier, an isolation stage, and an output stage. The CHB rectifier serves as an active rectifier to ensure that the input current is sinusoidal, and it converts the high AC input voltage to low DC voltages. The isolated DC/DC converters are then connected to the DC links and provide galvanic isolation between the HV and LV sides. Finally, a three-phase inverter generates the AC output with the desired amplitude and frequency. This paper introduces a new control strategy to maintain DC voltage balance among the CHB converter cells, even if the attached loads are different. The effects of voltage offsets and device mismatches on the equal load-current sharing are investigated, and an active load-current sharing method is presented to balance the load power among the parallel-output cells. The validity of the proposed controllers and the PET performance are verified by simulation and experimental results.