有源箝位软开关充电机的设计与仿真研究

传统硬开关电路影响效率和可靠性的同时,对其他设备的电磁干扰也较大,软开关则可解决上述问题。本文提出了一种基于辅助谐振换流的新型ZVT-PWM变换器,即通过采用简单的有源辅助谐振网络实现了主、辅开关管的软开关,主开关管实现了零电压开通,开关管电流电压应力小。利用这种软开关技术研制了一台用于为风力发电蓄电池充电的充电机,给出了充电机的控制系统框图,简单介绍了充电机的工作原理。最后利用Pspice给出了运行波形和仿真结果。     

电动汽车镍氢充电器的设计

本文介绍了一种2.4KW用于电动汽车的高频软开关镍氢充电器,该充电器主充电电路采用零电压零点流全桥PWM逆变器,移相芯片UCC3895作为调节器,单片机ATMEGA8作为辅助控制器,实现对镍氢电池的智能三段式充电.     

电动汽车镍氢充电器的设计

介绍了一种2.4kW用于电动汽车的高频软开关镍氢充电器,该充电器主充电电路采用零电压零电流全桥PWM逆变器,移相芯片UCC3895作为调节器,单片机ATMEGA8作为辅助控制器,实现对镍氢电池的智能三段式充电。     

电动汽车镍氢充电器的设计

介绍了一种2.4kW用于电动汽车的高频软开关镍氢充电器,该充电器主充电电路采用零电压零电流全桥PWM逆变器,移相芯片UCC3895作为调节器,单片机ATMEGA8作为辅助控制器,实现对镍氢电池的智能三段式充电。     

LLC谐振全桥变换器在交流传动电力机车充电机中的应用

用于交流传动电力机车的大功率蓄电池充电机的工作效率要求在90％以上,采用硬开关技术的开关电源难以达到要求。文章将LLC谐振全桥变换器应用到交流传动电力机车充电机中,分析了该变换器的工作原理,提出了一套完整的谐振参数设计方法,并结合SG2525调频控制技术,设计了一款容量为3．5kW的LLC谐振全桥变换器。实验证明该变换器工作稳定,在全输入和全负载范围内都实现了开关管的ZVS,保证电路在高频下的高效运行,达到了交流传动电力机车充电机的要求。     

Dual-bridge LLC-SRC with extended voltage range for deeply depleted PEV battery charging

This paper proposes a dual-bridge LLC series resonant converter with hybrid-rectifier for achieving extended charging voltage range of 50–420 V for on-board battery charger of plug-in electric vehicle for normal and deeply depleted battery charging. Depending upon the configuration of primary switching network and secondary rectifier, the proposed topology has three operating modes as half-bridge with bridge rectifier (HBBR), full-bridge with bridge rectifier (FBBR) and full-bridge with voltage doubler (FBVD). HBBR, FBBR and FBVD operating modes of converter achieve 50–125, 125–250 and 250–420 V voltage ranges, respectively. For voltage above 62 V, the converter operates below resonance frequency zero voltage switching region with narrow switching frequency range for soft commutation of secondary diodes and low turn-off current of MOSFETs to reduce switching losses. The proposed converter is simulated using MATLAB Simulink and a 1.5 kW laboratory prototype is also built to validate the operation of proposed topology. Simulation and experimental results show that the converter meets all the charging requirements for deeply depleted to fully charged battery using constant current-constant voltage charging method with fixed 400 V DC input and achieves 96.22% peak efficiency.     

Design and implementation of a battery charger with a state-of-charge estimator

In this paper, a novel integrated system for a battery charger with a state-of-charge estimator is proposed. First, by using a 16-bit MC80196 microprocessor, two different methods for estimating a battery's state-of-charge are presented. Then, the current of the charger is adjusted according to the estimated result. The charger, which has a zero current switching topology, performs with both a high input power factor and a high efficiency. In addition, the microprocessor effectively integrates the charger and the state-of-charge estimator. Several experimental results validate the theoretical analysis.     

节能型单相全桥谐振极逆变器

单相全桥逆变器处于硬开关状态时,随着开关频率的增大,开关损耗明显增大,影响逆变器效率的提高.为解决这一问题,提出了一种节能型单相全桥谐振极逆变器,在逆变器处于死区状态时,将要开通的主开关并联的谐振电容的电压能减小至零,主开关动作时能完成零电压软切换,双向辅助开关动作时能完成零电流软切换.讨论了电路的工作流程,实验结果表明主开关和辅助开关完成了软切换动作.该单相全桥软开关逆变器可以向高开关频率的场合推广应用.     

一种新颖的双模态LLC谐振变换器的分析与设计

为了提高LLC谐振变换器的输入电压适应范围,提出了一种新颖的双模态LLC谐振变换器。所提出变换器的隔离变压器原边绕组中设计有一个辅助抽头,使得变压器具有两种工作变比,对应两种工作模态：低输入电压区模态和高输入电压区模态。通过检测输入电压控制高频开关,使得变换器自动选择适应当前输入电压的工作模态。文中给出了所提出变换器的详细工作原理和换流过程分析。为了避免变换器在设定的输入电压切换点附近因模态连续切换而产生的震荡,提出了一种基于电压滞环和模态保持的模态切换策略。最后,研制了一台300W的实验样机,样机输入电压为25V~60V,控制芯片为TMS320F28335,样机实验结果验证了所提出的双模态LLC谐振变换器及其模态切换策略的可行性。     

The novel resonant DC link three-level soft-switching inverter

ABSTRACT

In the paper, the novel topology of the resonant DC link three-level soft-switching inverter is proposed to reduce switching losses and improve the efficiency of three-level inverter at high switching frequency. Symmetrical auxiliary resonant circuits are set in the DC link of three-level hard-switching inverter. Moreover, the terminal voltage of the resonant capacitors between the DC buses periodically drops to zero via the resonance of auxiliary circuits. Furthermore, under such condition, the main switches of the three-level inverter would be operated, in order to achieve zero-voltage switching. Based on the equivalent circuits in different operating modes, the paper analyses the working process of the soft-switching inverter in detail. In addition, a 3 kW laboratory prototype of resonant DC link three-phase three-level soft-switching inverter is built. The experimental results show that the main switches and auxiliary switches of the inverter are operated under soft-switching conditions, and the efficiency is significantly improved compared with the three-level hard-switching inverter. Therefore, the proposed topology can effectively reduce switching losses and prove to be more practical in engineering.     

基于TSM102的高效率铅酸蓄电池充电器设计

针对当前市场上流行的铅酸蓄电池充电器充电效率过低,开关器件消耗的热功率过大,投入在散热装置上的成本过高,充电器体积太大等多种弊端,提出一种新型的低成本、高效率铅酸蓄电池充电器设计方案。     

基于电流控制的光伏太阳能充电器系统研究

提出一种基于电流控制的最大功率点跟踪方法用于光伏太阳能充电器,以DC/DC变换器中的Boost电路作为开关充电器,系统由一个光伏电池模块、一个基于Boost变换器开关电池充电器和电池组成.采用光伏电池输出电流控制实现系统的最大功率点跟踪,调整占空比,从而使太阳电池阵列输出功率最大,以输出稳定的电压对蓄电池进行充电,可以提高蓄电池使用寿命,有效地提高独立光伏系统的综合效率,降低整个系统的成本.     

An improved automotive power distribution system using nonlinearresonant switch converters

An improved automotive electrical system is proposed in which the generator is a high-efficiency AC machine connected to the battery by an AC-DC converter. The electrical loads are isolated from the battery by a DC-DC converter. This will allow gradual conversion to higher battery voltage, regulation of DC distribution voltage, and multiple distribution voltage levels. In the low-voltage, high-current, high-temperature environment of the automobile, in addition to packaging and thermal management, a major problem is the switching loss caused by leakage, package, and other parasitic inductances. The nonlinear resonant switch can remove this source of loss, achieving zero current switching without sacrificing conduction loss or MOSFET switch utilization. For the nonlinear resonant switch in a 1.5 kW load converter application, the upper limit is approximately 20 nH. Hence, device interconnections have low inductance, and MOSFET package inductances are taken into account. A low-voltage, high-current nonlinear resonant switch converter operating at 700 kHz an producing 600 W is described     

A Novel Robust Control Method for the Series–Parallel Resonant Converter

A novel robust control method for the series–parallel resonant converter (SPRC), which moves the inverter switching point to switch in advance or with lag w.r.t. the rectifier commutation point (RCP), thereby varying the converter gain around the load-independent point, is presented. The converter gain is derived using a novel analytical tool that combines state-plane analysis and superposition with added RCP constraint. Unlike traditional fundamental harmonic analysis , the exact gain and frequency expressions for the SPRC at the load-independent point and its neighborhood are obtained with this method. The proposed gain adjustment technique is combined with feedback to form a simple resonant converter controller. This control method is shown to be highly robust to resonant tank parameter uncertainty and circuit/switching delay. It also significantly simplifies the resonant converter controller's design.      

High-performance online UPS using three-leg-type converter

A high-performance single-phase online uninterruptible power supply (UPS) is proposed. The UPS is composed of a three-leg-type converter which operates as a battery charger and an inverter. The first leg is controlled to charge the battery, and the third leg is controlled to make the output voltage. The common leg is controlled in line frequency. The charger and the inverter are controlled independently. The charger has the capability of power-factor correction while charging a battery. The inverter regulates output voltage and limits output current under an impulsive load. The three-leg-type converter reduces the number of switching devices. As a result, the system has less power loss and a low-cost structure. In the determination of the charger voltage, the nominal voltage is derived using the feedback linearization concept and then a perturbed voltage is determined for the reactive power control. The disturbance of input voltage is detected using a fast sensing technique of the input voltage. Experimental results obtained with a 3-VA prototype show a normal efficiency of over 87% and an input power factor of over 99%.     

磁耦合谐振式无线充电系统研究

无线充电技术是一种新型的电能传输技术。文中设计了一种磁耦合谐振式蓄电池充电器,能够实现蓄电池无线充电。利用两个发生谐振耦合的电路来捕捉随距离缩减的电磁场,当发射回路和接受回路处于谐振状态时,谐振体之间能量交换可以达到很高的效率。利用变压器互感模型对磁耦合谐振无线电能传送进行了分析,设计了功率为4 kW的磁耦合谐振频率75 kHz的试验电路,实验结果表明,当传输距离为0.3 m时,效率接近90%。     

高效率单相全桥软开关整流器

单相全桥整流器工作在硬开关状态时,随着开关频率和输出功率的增大,开关损耗会显著增大,影响整流器效率的提高.为解决这一问题,提出了一种单相全桥软开关整流器,在整流器处于死区状态时,将要开通的主开关并联的谐振电容的电压能减小至零,主开关动作时能完成零电压软切换,双向辅助开关动作时能完成零电流软切换.分析了整流器的换流过程,实验结果表明主开关和辅助开关完成了软切换动作.因此,该单相全桥软开关整流器在高开关频率下能实现高效率运行.     

Voltage equaliser for Li–Fe battery

In this article, a voltage equaliser is proposed for a battery string with four Li–Fe batteries. The proposed voltage equaliser is developed from a flyback converter, which comprises a transformer, a power electronic switch and a resonant clamped circuit. The transformer contains a primary winding and four secondary windings with the same number of turns connected to each battery. The resonant clamped circuit is for recycling the energy of leakage inductance of the transformer and for performing zero-voltage switching (ZVS) of the power electronic switch. When the power electronic switch is switched on, the energy is stored in the transformer; and when the power electronic switch is switched off, the energy stored in the transformer will automatically charge the battery whose voltage is the lowest. In this way, the voltage of individual batteries in the battery string is balanced. The salient features of the proposed voltage equaliser are that only one switch is used, the energy stored in the leakage inductance of the transformer can be recycled and ZVS is obtained. A prototype is developed and tested to verify the performance of the proposed voltage equaliser. The experimental results show that the proposed voltage equaliser achieves the expected performance.     

A sub-nanosecond resonant-type monolithic T/R switch formillimeter-wave systems applications

This paper is concerned with the design consideration, fabrication process, and performance of a V-band monolithic transmit/receive (T/R) switch for millimeter-wave wireless networks applications. The developed switch integrated circuit (IC) has a novel structure in which to pass a signal, it presents a parallel resonant circuit to the signal by forward biasing a pair of switching heterojunction FET's (HJFETs), but to block the signal, it presents a series resonant circuit to the signal by reverse biasing the switching HJFETs. With a control voltage of 0/3.2 V, the developed T/R switch exhibits a minimum insertion loss of 3.9 dB, a maximum isolation of 41 dB, and a high switching speed of 250 ps, over 57-61 GHz. The monolithic T/R switch chip size is 3.3 mm×1.7 mm     

Resonant gate driver with efficient gate energy recovery and switching loss reduction

This article describes a novel resonant gate driver for charging the gate capacitor of power metal-oxide semiconductor field-effect-transistors (MOSFETs) that operate at a high switching frequency in power converters. The proposed resonant gate driver is designed with three small MOSFETs to build up the inductor current in addition to an inductor for temporary energy storage. The proposed resonant gate driver recovers the CV² gate loss, which is the largest loss dissipated in the gate resistance in conventional gate drivers. In addition, the switching loss is reduced at the instants of turn on and turn off in the power MOSFETs of power converters by using the proposed gate driver. Mathematical analyses of the total loss appearing in the gate driver circuit and the switching loss reduction in the power switch of power converters are discussed. Finally, the proposed resonant gate driver is verified with experimental results at a switching frequency of 1 MHz.