基于LPC2214的ZVZCS-PWM全桥变换控制器的研究

针对传统ZVZCS-PWMDC／DC全桥变换器在实现滞后桥臂开关管零电流开关过程中,存在着辅助谐振电路附加损耗较大,软开关实现方式复杂,功率开关管电压应力和电流应力高等缺点,介绍了一种新型次级箝位移相控制的ZVZCSPWMDC／DC全桥变换器。文中分析了该变换器实现软开关的原理,同时设计了变换器数字控制系统,控制器采用LPC2214型ARM芯片,并通过一台实验样机验证了这种软开关变换器相关理论的正确性以及该数字控制系统的可行性。     

Zero-voltage and zero-current-switching PWM hybrid full-bridge three-level converter

This paper proposes a zero-voltage and zero-current-switching pulsewidth modulation hybrid full-bridge three-level (ZVZCS PWM H-FB TL) converter, which has a TL leg and a two-level leg. The voltage stress of the switches of the TL leg is half of the input voltage, and the switches can realize ZVS, so MOSFETs can be adopted; the voltage stress of the switches of the two-level leg is the input voltage, and the switches can realize ZCS, so IGBT can be adopted. The secondary rectified voltage is a TL waveform having lower high-frequency content compared with that of the traditional FB converters, which leads to the reduction of the output filter inductance. The input current of the converter has quite little ripple, so the input filter can also be significantly reduced. The operation principle of the proposed converter is analyzed and verified by the experimental results. Several ZVZCS PWM H-FB TL converters are also proposed in this paper.     

Family of Soft-Switching PWM Converters With Current Sharing in Switches

In this paper, a new family of soft-switching pulsewidth modulation (PWM) converters is introduced. In this family of converters, two switches operate out of phase and share the output current while providing soft-switching condition for each other. A buck converter, from this family of converters, is analyzed and its operating modes are discussed. The adoption of regular PWM control circuit to the proposed converters is presented. A prototype converter is implemented and its experimental results are illustrated.     

Novel zero-voltage and zero-current-switching (ZVZCS) full-bridge PWM converter using coupled output inductor

A novel zero-voltage and zero-current-switching (ZVZCS) full-bridge pulse-width-modulated (PWM) converter is proposed to improve the previously proposed ZVZCS full-bridge PWM converters. By employing a simple auxiliary circuit with neither lossy components nor active switches, soft-switching of the primary switches is achieved. The proposed converter has many advantages such as simple auxiliary circuit, high efficiency, low voltage stress of the rectifier diode and self-adjustment of the circulating current, which make the proposed converter attractive for the high voltage and high power applications. The principles of operation and design considerations are presented and verified on the 4 kW experimental converter operating at 80 kHz.     

采用辅助变压器的零电压零电流开关全桥直-直变换器

本文给出了一种新型的零电压零电流开关全桥移相脉宽调制变换器,该变换器采用IGBT为功率开关管,在传统变换器的基础上通过增加辅助变压器的方式提高了变换器的性能,通过增加正激能量恢复缓冲器和辅助电路,使变换器在各种负载以及短路工作状态下都能够保证所有开关管实现零电压零电流开关工作模式。介绍了变换器的工作原理并通过试验得到了较好的结果。     

Novel zero-voltage and zero-current-switching full bridge PWMconverter using transformer auxiliary winding

A novel zero voltage and zero current switching (ZVZCS) full bridge (FB) pulse width modulation (PWM) converter is proposed to improve the demerits of the previously presented ZVZCS-FB-PWM converters, such as use of lossy components or additional active switches. A simple auxiliary circuit which includes neither lossy components nor active switches provides ZVZCS conditions to primary switches, ZVS for leading-leg switches and ZCS for lagging-leg switches. Many advantages including simple circuit topology, high efficiency, and low cost make the new converter attractive for high power (>2 kW) applications. The operation, analysis, features and design considerations are illustrated and verified on a 2.5 kW, 100 kHz insulated gate bipolar transistor (IGBT) based experimental circuit     

Zero-voltage and zero-current-switching full-bridge PWM converterusing secondary active clamp

A new zero-voltage and zero-current-switching (ZVZCS) full-bridge (FB) pulse width modulation (PWM) power converter is proposed to improve the performance of the previously presented ZVZCS FB PWM power converters. By adding a secondary active clamp and controlling the clamp switch moderately, ZVS (for leading-leg switches) and ZCS (for lagging-leg switches) are achieved without adding any lossy components or the saturable reactor. Many advantages, including simple circuit topology, high efficiency and low cost, make the new power converter attractive for high-voltage and high-power (>10 kW) applications. The principle of operation is explained and analyzed. The features and design considerations of the new power converter are also illustrated and verified on a 1.8 kW 100 kHz IGBT-based experimental circuit     

An improved family of ZVS-PWM active-clamping DC-to-DC converters

A new family of DC-to-DC converters featuring clamping action, PWM modulation and soft-switching (ZVS) in both active and passive switches, is proposed to overcome the limitations of clamped mode DC-to-DC converters. The new family of converters is generated and the new circuits are presented. As the resonant circuits absorb all parasitic reactances, including transistor output capacitance and diode junction capacitance, these converters are suitable for high-frequency operation. Principle of operation of the boost converter, theoretical analysis, simulation and experimental results are presented, taken from a laboratory prototype rated at 1600 W, input voltage of 300 V, output voltage of 400 V, and operating at 100 kHz. The measured efficiency at full load was 98%     

Zero-Voltage and Zero-Current Switching Full-Bridge DC–DC Converter With Auxiliary Transformer

A novel zero-voltage and zero-current switching (ZVZCS) full-bridge phase-shifted pulsewidth modulation (PWM) converter using insulated gate bipolar transistors (IGBTs) with auxiliary transformer is proposed to improve the properties of the previously presented converters. ZVZCS for all power switches is achieved for full load range from no-load to short circuit by adding active energy recovery snubber and auxiliary circuits. The principle of operation is explained and analyzed and experimental results are presented. The features and design considerations of the converter are verified on a 3-kW, 50-kHz IGBT based experimental circuit.     

Soft-switching techniques in PWM converters

A number of soft-switching pulse-width-modulated (PWM) converter techniques have been proposed, aimed at combining the desirable features of both the conventional PWM and resonant converters while avoiding their respective limitations. In this paper, three classes of zero-voltage soft-switching (PWM) converters (namely the zero-voltage-switched (ZVS) quasi-square-wave converters, ZVS-PWM converters, and zero-voltage-transition PWM converters) and two classes of zero-current soft-switching PWM converters (namely, the zero-current-switched PWM converters and zero-current-transition PWM converters) are reviewed, and their merits and limitations are assessed. Experimental results of several prototype of converters are presented to illustrate each class of converter     

A family of zero-voltage and zero-current-switching (ZVZCS) three-level DC-DC converters with secondary-assisted regenerative passive snubber

A detailed analysis and optimized-oriented design of a family of three-level soft-switching converters is presented. The zero-voltage-switching (ZVS) of the outer switches and zero-current-switching (ZCS) of the inner switches is realized by employing a pulse-width-modulation (PWM) phase-shift control and a secondary-assisted passive snubber. The switching operation is discussed by comparing the results produced by the use of different passive snubbers (the author's original one and literature-available ones). The voltage on the rectifier diodes is clamped at a reasonable value, specific to each one of the six snubbers taken into consideration. The voltage stress on each transistor is reduced to half of the input voltage. Lower rated transistors and rectifier diodes can be used, thus reducing the conduction losses. Before turning on/off the inner switches, the snubber's capacitor voltage determines the fall of the primary current to zero, thus avoiding wasteful energy circulation and assuring ZCS. The snubber's energy is recuperated to the load. The outcome of these improvements is a high efficiency in energy processing. Soft-switching-oriented constraints on the converter parameters are expressed as implicit equations, whose graphical solution permits the optimized design of the parameters in order to ensure ZVZCS. A comparative analysis of the effective duty cycle and the boost effect of it, due to the use of the secondary snubber, is performed. The influence of the choices of the parameters values on the regulation capability is pointed out. Experimental results prove the expected high performances of the optimized converters.     

Lossless passive soft-switching methods for inverters andamplifiers

This paper proposes lossless passive soft-switching methods for inverters developed from a synthesis procedure applicable to all pulsewidth modulation (PWM) converters. The lossless passive soft-switching converter properties and synthesis procedure are derived for inverters. Promising full-bridge and half-bridge soft-switching inverter examples are shown from the synthesis results. These include a new soft turn-on full bridge that contains only six components and a new soft turn-on and turn-off half bridge that contains 12 components. The voltage stress across the active switches can be easily maintained below 125% of V_bus. Additionally, no transformers are used for energy recovery, eliminating their associated diode stress and leakage inductance problems. The theoretical and experimental waveforms and analysis are given     

A Zero-Voltage and Zero-Current Switching Three-Level DC–DC Converter With Reduced Rectifier Voltage Stress and Soft-Switching-Oriented Optimized Design

A novel zero-voltage zero-current switching (ZVZCS) three-level converter with pulsewidth modulation (PWM) phase-shift control is proposed. The ZCS of the lagging switch is obtained by using a regenerative passive snubber in the secondary. In order to reduce the voltage stress on the rectifier's diodes, a few passive elements are inserted into the primary: a small inductance, two diodes, and a small additional winding of the main transformer. In each half-cycle, one of these diodes will conduct for a short time in order to clamp the voltage of the snubber's capacitor, and thus, the rectifier stress, at$(n_2/n_1)(V_ in/2)$,$n_1$, and$n_2$being the transformer's primary and, respectively, secondary turns number. The three-level configuration allows for the reduction of the voltage stress across the power switches to half of the input voltage$V_ in$. The conditions for assuring ZVS of the leading switch and ZCS of the lagging switch are found. Design constraints on the parallel capacitances of the switches of the leading switch, on the snubber's holding capacitor, and on the additional inductance and winding are hence established, allowing for an optimized design of the converter parameters. A dc analysis allows for the calculation of the effective duty cycle, which enjoys a boost effect due to the proposed snubber. Thus, a further reduction of the primary current stress and rectifier voltage stress is obtained. All the improvements conclude in a high efficiency. The influence of the choice of the parameters' values on the regulation capability is pointed out. Experiments on a prototype of 4.5kW confirm the results.     

A passive soft-switching snubber for PWM inverters

This paper presents a regenerative passive snubber circuit for pulse-width modulation (PWM) inverters to achieve soft-switching purposes without significant cost and reliability penalties. This passive soft-switching snubber (PSSS) employs a diode/capacitor snubber circuit for each switching device in an inverter to provide low dv/dt and low switching losses to the device. The PSSS further uses a transformer-based energy regenerative circuit to recover the energy captured in the snubber capacitors. All components in the PSSS circuit are passive, thus leading to reliable and low-cost advantages over those soft-switching schemes relying on additional active switches. The snubber has been incorporated into a 150 kVA PWM inverter. Simulation and experimental results are given to demonstrate the validity and features of the snubber circuit.     

Simple topologies of PWM AC-AC converters

This letter proposes a new family of simple topologies of PWM AC-AC converters with minimal switches. With extension from the basic DC-DC converters, a series of AC-AC converters such as buck, boost, buck-boost, Cuk, and isolated converters are obtained. By PWM duty ratio control, they become a "solid-state transformer" with a continuously variable turns ratio. All the proposed AC-AC converters in this paper employ only two switches. Compared to the existing circuits that use six switches or more, they can reduce cost and improve reliability. The operating principle and control method of the proposed topologies are presented. Analysis and simulation results are given using the Cuk AC-AC converter as an example. The analysis can be easily extended to other converters of the proposed family.     

Novel zero-voltage-transition PWM converters

To date, soft-switching techniques applied to the PWM converters, with the exception of a few isolated cases, are subjected to either high switch voltage stresses or high switch current stresses, or both. A new class of zero-voltage-transition PWM converters is proposed, where both the transistor and the rectifier operate with zero-voltage switching and are subjected to minimum voltage and current stresses. Breadboarded converters are constructed to verify the novelty of the proposed new family of converters     

软开关半桥DC/DC变换器的PWM控制策略分析

文章根据控制型软开关半桥DC/DC变换器的定义,总结和归纳了4种控制型软开关半桥DC/DC变换器的PWM控制策略和缓冲型软开关半桥DC/DC变换器对称PWM控制策略。对上述PWM控制策略进行了深入分析和综合比较,为选择具体应用场合提供了依据。     

软开关PWM变换器发展综述

软开关技术已从基本谐振变换器,准谐振变换器和谐振直流环节变换器发展到软开关ＰＷＭ变换器。软开关ＰＷＭ变换器综合了软开关技术和ＰＷＭ技术各自的优点,构成新一类目前发展和应用前景的变换器。本文系统地综述了谐振直流环变换器,零电压和零电流开关ＰＷＭ变换器,零电压转换ＰＷＭ变换器和零电流转换ＰＷＭ变换器的工作原理和特点。     

A Multipulse-Structure-Based Bidirectional PWM Converter for High-Power Applications

Multipulse converters are suitable for high-power application with the merits of low switching frequency and perfect harmonic performance. But less controllability and poor regulation lead the restriction on its application. A bidirectional pulsewidth modulation (PWM) converter based on multipulse structure is proposed in this paper, which has the same perfect harmonic performance with very low switching frequency. A special sequential sampling space vector modulation technique, which has the sampling sequence from the lagging module to the leading module, is proposed to make the converter controllable like conventional PWM converters. The harmonic performance and linear regulation capability are analyzed theoretically. The converter is modeled in detail, and an instantaneous feedback control strategy with phase delay compensation and decoupling control is also proposed. The controller parameters are optimized to get high dynamic performance with adequate phase margin and gain margin. A 3-kVA prototype is built, and the simulation and experiment results validate that the proposed converter is quite suitable for high-power conversion.     

Single-phase Z-source PWM AC-AC converters

The letter proposes a new family of simple topologies of single-phase PWM ac-ac converters with a minimal number of switches: voltage-fed Z-source converter and current-fed Z-source converter. By PWM duty-ratio control, they become "solid-state transformers" with a continuously variable turns ratio. All the proposed ac-ac converters in this paper employ only two switches. Compared to the existing PWM ac-ac converter circuits, they have unique features: providing a larger range of output ac voltage with buck-boost, reversing or maintaining phase angle, reducing in-rush and harmonic current, and improving reliability. The operating principle and control method of the proposed topologies are presented. Analysis, simulation, and experimental results are given using the voltage-fed Z-source ac-ac converter as an example. The analysis can be easily extended to other converters of the proposed family. The proposed converters could be used in voltage regulation, power regulation, and so on.