Zero-current Switching Series Resonant High-voltage DC-DC Converter with Series-connected Primary Windings of Center-tapped Transformer

Abstract—This article proposes a novel zero-current switching series resonant inverter-fed voltage multiplier based high-voltage DC-DC converter. The series resonant inverter in the proposed topology has two power switches (insulated-gate bipolar transistors), two resonant capacitors, and only one high-voltage transformer with center-tapped primary windings. The power switches are connected in the form of a half-bridge network. The leakage inductances of the transformer's primary windings together with resonant capacitors form two series resonant circuits. The series resonant circuits are fed alternately by operating power switches with an interleaved half-switching cycle. The secondary winding of the high-voltage transformer is connected to a voltage multiplier circuit to rectify and boost the voltage. The converter operates in discontinuous conduction mode, and its output voltage is regulated by pulse-frequency modulation. Therefore, all the power switches turn ON and OFF at the zero-current switching condition. The main features of the proposed converter are lower power loss, less cost, and smaller size compared to previously proposed series resonant high-voltage DC-DC converters. The experimental results of a 130-W prototype of the proposed converter are presented both for dynamic and steady-state operation. The results confirm the excellent operation and performance of the converter.     

Representation of noise in a particular type of linear n-port network

A noisy linear N-port network that can be represented by a noise-free linear N-port network with voltage and current noise sources at the ports is considered. If the linear N-port network has a particular type of admittance matrix, it is possible to show that as many as N/2 when N is even and (N – 1)/2 when N is odd of the ports may be cleared of noise sources. The total number of unique representations of such a network is given for both the general case and for the case when a particular port or ports must be free of noise sources.     

Learning feedback controller design of switching converters via MATLAB/SIMULINK

The application of MATLAB/SIMULINK is developed for simulation and learning feedback controller design of DC-DC switching converters. With the help of its intuitive graphical user interface and some basic circuit theories, the corresponding SIMULINK models of the switching converter circuits can be easily constructed. Students can then use these models to learn and evaluate the closed-loop behavior of the entire system in the MATLAB/SIMULINK environment, after feedback controllers are devised by any classical or modern control theory. The accuracy of this approach is also verified by comparing the simulation results with the responses obtained from a buck-type DC-DC switching converter circuit and existing experimental results.     

用无源技术实现软开关式高频PWM变换器的研究

本文提出了应用于高频PWM变换器上的无源软开关技术应当满足的五个基本要求。以应用于非隔离型DC-DC PWM变换器上的典型无源软开关电路为例,对这些电路特性进行简要的比较分析。对其中的电荷泵再生型无源软开关新技术进行了深入的分析与研究;从该电路中提取出一个电荷泵再生型无源软开关元胞CPR,以此为基础,将CPR推广应用到基本的非隔离型DC-DC PWM变换器上。对应用于Boost变换器的无源软开关电路进行了理论分析与实验测试,表明它能基本满足前述的五个基本要求。     

Sufficient conditions for the unique solvability of linear networks containing memoryless 2-ports

Combinatorial necessary and sufficient conditions for the unique solvability of linear networks containing n-ports are well known for the ‘general’ case. They are only necessary if relations among n-port parameters are also taken into consideration. In the present paper combinatorial sufficient conditions are presented for linear networks containing RLC elements and memoryless 2-ports. The somewhat surprising result is proved that whether a 2-port can cause certain types of singularities can be predicted before the interconnection. A concept, similar to the normal tree (which intersects ideal transformers by one, gyrators by two or no edges) is introduced for arbitrary 2-ports. Its existence implies unique solvability. Relations to previous results and algorithmical aspects are also discussed.     

一种新型全桥零电压转模 PWM DC-DC变换器

针对移相全桥ZVS PWM DC-DC变换器滞后桥臂零电压开关范围窄、占空比丢失严重以及转换效率较低等缺点，该文提出了一种新型的全桥ZVT PWM DC-DC变换器拓扑。这种电路在传统移相ZVS PWM DC-DC变换器的基础上增加了两个无源网络，其中一个并联在原边的主电路中，为滞后桥臂实现零电压开关提供条件；另一个串联在变压器的副边，以减小变压器的导通损耗。这种电路有宽零电压负载范围，占空比丢失小等优点，可以提高了开关电源的效率，且输出性能好。该文分析了变换器的工作原理以及滞后桥臂零电压开关的实现条件。该文采用了DSP作为控制芯片，实现了系统的双闭环控制。最后研制了一台功率为600W，工作频率为100kHz的样机，实验结果验证了这种新型全桥ZVT PWM DC-DC变换器相关理论的正确性。     

Realization of n-port resistance matrices

The problem of realization of a given real symmetric matrix R of order n as an open-circuit resistance matrix of some resistive n-port network having nullity n is considered in this paper. The solution presented is in the form of a realization technique which implies the necessary and sufficient conditions for this type of realization. Derived from fundamental topological considerations in the analysis of resistive n-port networks, the realization technique presented here is found to be superior to the existing ones.     

一类基本双频DC-DC变换器

从开关电感三端网络旋转得到基本DC-DC变换器出发,提出了双频开关电感三端网络和一类基本双频DC-DC变换器拓扑结构.该双频DC-DC变换器中包含高频开关单元和低频开关单元,其中低频单元主要承担处理功率的功能,高频单元主要用于提高系统性能.低频单元为高频开关分流,使高频部分可工作在很高的频率用于提高动态响应速度.并以双频Buck变换器为例,对其稳态和动态特性进行了分析,提出了改进措施来提高动态响应速度.理论分析和实验结果均验证了双频Buck变换器的输出性能与单个高频Buck变换器一致.     

应用抽头扼流圈扩展基本DC-DC开关变换器的变换功能

本文论述了在基本DC-DC开关变换器中应用抽头扼流圈扩展其变换性能，推导了基本关系式，并对两种不同型式的变换器的变换性能进行了比较。     

Design and analysis of a high step-up single-switch coupled inductor DC-DC converter with low-voltage stress on components for PV power application

This paper presents a single-switch, high step-up, non-isolated DC-DC converter for photovoltaic (PV) power application. The proposed converter is composed of a coupled inductor, a passive clamp circuit, a voltage multiplier cell, and a voltage lift circuit. The passive clamp circuit recovers the leakage inductance energy of the coupled inductor and limits the voltage spike on the switch. Configuration of the passive clamp and voltage multiplier circuits increases the converter voltage gain. High-voltage gain without a large duty cycle, low turn ratio of the coupled inductor, low-voltage stress on the switch and diodes, leakage inductance energy recovery, and high efficiency are the main merits of the suggested DC-DC converter. Steady-state operation of the converter in continuous conduction mode (CCM), discontinuous conduction mode (DCM), and boundary condition mode (BCM) is discussed and analyzed in detail. Then, design procedure of the proposed converter is given. The presented DC-DC converter is compared with similar topologies to verify its advantages. Moreover, theoretical efficiency of the presented converter is calculated in details. Finally, simulation and experimental measurement results of 388 V-220 W prototype of the proposed DC-DC converter at 50-kHz switching frequency are presented to verify its performance.     

开关DC-DC变换器双频率脉冲序列调制技术

提出一种新颖的开关DC-DC变换器调制方法:双频率脉冲序列调制(bi-frequency pulse train modulation,BF-PTM)方法。BF-PTM通过对两组频率不同、但导通时间相同的控制脉冲进行调制,实现开关变换器输出电压的调节。BF-PTM适用于各种开关变换器拓扑。以电感电流断续模式(discontinuous conduction mode,DCM)Buck变换器为例,分析BF-PTM开关变换器的工作原理及控制特性,并进行相应的仿真及实验研究。研究结果表明,BF-PTM控制开关变换器具有优于PWM开关变换器的瞬态响应和电磁干扰特性。     

Cascade decomposition of a passive 2n-port network

This paper deals with a cascade decomposition of a passive 2n-port network. after a basic discussion relative to complex- and unit-normalized scattering matrices, necessary and sufficient conditions are presented under which given lossless 2n-ports D₁ and D₂ are simultaneously extractable from the front- and back-ends of the passive 2n-port N, respectively, to leave a passive 2n-port remainder Ne. Based on these conditions, some relations between the individual and simultaneous extractability of D₁ and D₂ from N for both degenerate and non-degenerate remainders N_e are discussed. the results are presented in terms of scattering as well as impedance matrices and can be considered as an extension of those given in Reference 1.     

Infinite networks of positive operators

Infinite resistive networks have recently been analyzed by H. Flanders. The present work is an extension of Flanders results in three directions:

• (1) It analyzes the more general case where the resistances in the network are positive bounded linear operators on a Hilbert space H and the currents and voltages are members of H.
• (2) An infinite number of sources is now allowed.
• (3) The network is permitted to have finite loops of doubly infinite paths consisting entirely of short circuits.

Conditions are developed under which existence and uniqueness theorems for the set of branch currents can be stated. These conditions include the requirement that all branch resistances be either zero or invertible. The situation where some or all of the resistances have nontrivial null spaces is also considered. In those cases where the branch currents need not be unique for a given set of sources, the difference between two possible current distributions can be characterized as a current distribution that produces zero voltage drops in all branches. An application to time-varying resistive networks containing switches is also given.     

Energy-related concepts for non-linear time-varying n-ports: Passivity and losslessness

Definitions of passivity and losslessness are presented that apply to n-port networks which are not necessarily linear, time-invariant, or lumped; in fact, these definitions apply to any n-port that has an abstract dynamical system representation. For lumped, non-linear n-port networks that can be mathematically represented by a finite-order dynamical system, conditions for passivity and losslessness are formulated in terms of properties of the state equation function, the output function, etc. These conditions can be verified without solving the state equation, and can be viewed as non-linear generalizations of the well-known time-domain and frequency-domain passivity and losslessness conditions for linear time-invariant lumped n-port networks.     

The existence and the determination of terminal equations for hybrid connected N-ports

A new procedure for the existence and the determination of terminal equations for the hybrid interconnection of two n-port networks is given. It is shown that this procedure generalizes the previous works of Duffin, Trapp and Mitra for the hybrid sum of terminal impedance matrices which are either Hermitian positive semi-definite (HSD) or arbitrary matrices with complex entries. For the application of the new procedure it is shown that each n-port need not be terminal solvable or well defined. In fact, even in the case of active RLC n-ports considered in sinusoidal steady-state, the previous results of Duffin, Mitra and Trapp established for HSD matrices or arbitrary complex matrices can still be utilized with the use of modified terminal equations, to obtain the terminal equations of the resulting n-port networks. It is also noted that the method introduced in this paper is independent of the choice of generalized inverses.     

On the number of conductances required for realizing Y and K matrices

Upper bounds are established on the number of conductances required for realizing a real symmetric matrix Y as the short-circuit conductance matrix of a resistive n-port network containing no negative conductances, and for the realization of a real matrix K as the potential factor matrix of a similar network without negative conductances. These results are the consequence of the properties of the modified cut-set matrix of an n-port and a theorem in the theory of linear programming.     

Effective Suppression of Conducted Electro Magnetic Interference in DC-DC Boost Converter Using Field Programmable Gate Array Based Chaotic Pulse Width Modulation Switching

Abstract—In recent years, electro-magnetic interference on DC-DC converters is seen as serious problem as it limits the capability of the DC-DC converter. It is popular to use analog circuits to suppress electro-magnetic interference; however, a cheap analog circuit suffers from numerous drawbacks, including inaccurate pulse generation, carrier frequency limitation, and degraded performance due to aging. Conversely, high-performance digital circuits are capable of providing accurate pulses compared to analog circuits. In this article, a field-programmable gate array is used to generate accurate chaotic pulse-width modulation pulses for DC-DC converters. A spread spectrum technique based on randomized carrier frequency modulation with fixed duty ratio is proposed for gating pulse generation, implemented using a field-programmable gate array for electro-magnetic interference suppression. A hardware prototype is built in the laboratory for the proposed method and tested. The performance of the proposed method estimated through simulation study is validated via experimental results.     

DC—DC变换器中非线性现象研究的发展综述

DC-DC变换器电路有丰富的非线性特性,它们运行的一大特点是几个电路拓扑之间的循环切换,这就会产生各种不同的非线性特性。本文回顾了在DC-DC变换器电路观察到的混沌特性和分叉现象,列举了这方面相关的重要文献,着重说明电路运行的主要特件和建模方法。指出了从非线性动力学的角度去研究分叉与混沌行为是今后DC-DC变换器电路分析方法的一个发展方向。     

Circuit Techniques for Improving the Switching Loci of Transistor Switches in Switching Regulators

The use of switching regulator circuits at high power levels and high frequencies requires careful examination and control of the power dissipation during switching, which may be the dominant loss. In this paper it is shown that it is possible to remove most of the switching losses from the switching transistor with two networks, each containing three components: an inductor or a capacitor, a diode, and a resistor. With proper design, the power dissipation in the resistors is less than the switching losses removed from the switching transistor, resulting in some improvement in overall efficiency. In addition, it is possible to obtain a significant further improvement in efficiency by replacing the resistors in the networks with low loss circuits. Each network, one for the reduction of turnoff losses and one for the virtual elimination of turnon losses in the switching transistor, is described in detail. Analytical design procedures are included.