A 20 kHz hybrid resonant power source for the space station

A hybrid resonant inverter system is presented that satisfies the steady-state operating requirements of a power source for the proposed International Space Station mobile servicing system. The steady-state behavior of the inverter was analyzed and a method is described for optimizing the design of the resonant network. The performance characteristics such as the total harmonic distortion of the output voltage, RMS output voltage, and the inverter efficiency are presented. The hybrid resonant inverter system maintains an excellent efficiency over varying output-load demand     

Analysis of parallel resonant converter operating above resonance

A high-frequency DC-DC converter using a parallel resonant inverter operating above resonance is analyzed using a state-space approach and a constant current model. Closed-form solutions are obtained under steady-state conditions. The analysis shows that with some changes most equations are of the same form as those corresponding to operations below resonance. The analysis is also used to obtain the design curves and to provide a simple design procedure, which is illustrated by a design example. Experimental results obtained with a prototype MOSFET unit (using metal-oxide-semiconductor field-effect transistors as switches and operating above 90 kHz) are presented to support the theory     

Novel single-stage half-bridge series-resonant buck-boost inverter

A novel single-stage half-bridge series-resonant buck-boost inverter (HB-SRBBI) is proposed. The main attribute of the novel inverter topology is the fact that it generates an ac output voltage larger or lower than the dc input one, depending on the instantaneous duty cycle. This property is not found in the classical voltage source inverter (VST), which produces an ac output instantaneous voltage always lower than the dc input voltage. The proposed inverter circuit topology provides the main switch for turn-on at zero-current-switching (ZCS) by an auxiliary resonant cell built before the output choke. A state-space averaging approach is employed to analyze the system. A design example of 500 W ac/dc inverter is examined to assess the inverter performance and it provides high power efficiency above 90.7% under the rated power.     

Improved DC/AC interface inverter for high-frequency spaceapplications

A DC/AC interface inverter for a high-frequency space power distribution system that uses dual asymmetrical resonant bridges is examined. Compared to the conventional approach in which two symmetrical bridges are used, the asymmetrical bridges arrangement offers better use of the installed kVA rating and efficiency of the inverter system. A simplified approach for modeling the inverter system in steady-state is presented, and a criteria to select the resonant components is given. A detailed simulation is performed for the following: a symmetrical inverter system with a resistive load, an asymmetrical inverter system with a resistive load, and an asymmetrical inverter system with the type-1A AC/DC converter load     

Design of the Series Resonant Converter for Minimum Component Stress

For a given output voltage and power, the peak resonant capacitor voltage and peak inductor and switch currents of the series resonant converter depend strongly on the choice of transformer turns ratio and of tank inductance and capacitance. In this paper the particular component values which result in the smallest component stresses are determined, and a simple design strategy is developed. The procedure is illustrated for an off-line 200 W, 5 V application, and it is shown that an incorrect choice of component values can result in significantly higher component stresses than are necessary.     

Analysis of a parallel resonant converter with secondary-sideresonance

A high-frequency (HF) link parallel resonant DC/DC converter operating in the lagging power factor mode with the resonating capacitor on the secondary side of the HF transformer is analyzed using a state-space approach. Closed-form solutions (except for the duration of diode conduction) are obtained for steady-state conditions, and design curves are obtained. A method of obtaining optimum operating point under certain constraints is developed and is used as the basis of a simple design procedure. A theoretical study comparing the performance of three MOSFET-based 1-kW converters with different transformer turn ratios under load changes from rated-load to 10% load is carried out. Experimental results obtained with these converters with different transformer turn ratios are also presented     

Resonant inverters for photovoltaic array to utility interface

A number of high-frequency link power converter schemes suitable for interconnecting a photovoltaic (PV) array to the utility line using resonant inverters are presented. Use of high-frequency resonant inverters (HFRI) results in reduced size, weight and cost. Scheme 1 uses the HFRI-cycloconverter, scheme 2 uses the HFRI-rectifier pulsewidth-modulated voltage source inverter, scheme 3 uses the HFRI-rectifier line commutated inverter working with a fixed maximum possible inverting fringe angle, and scheme 4 uses the HFRI-rectifier line-connected inverter (with line current modulation). These schemes are compared. Based on the comparison, scheme 3 was selected for an initial study. To overcome various problems associated with scheme 3, the line current is modulated sinusoidally in scheme 4. In this scheme, the HFRI is controlled appropriately to obtain a rectified sine wave of 120 Hz in the DC link and the function of the line-connected inverter is to unfold this waveform on alternate half cycles to obtain a sinusoidal line current with the line voltage. Methods of commutation of the line connected inverter are explained. Experimental results obtained with scheme 4 are presented     

A new resonant link aircraft power generating system

A 400 Hz aircraft power generating system which has been designed to achieve significant improvements in power density and reliability is introduced. Design targets for this exploratory development program include system (generator-plus-converter) power density of 1 kVA/lb and mean-time-between-failure (MTBF) of 500 h. At the heart of the new variable-speed constant-frequency (VSCF) configuration is a high-frequency resonant link inverter designed so that all inverter switching occurs under zero-voltage conditions. Advantages include minimization of switching losses and significant reductions in power device switching stresses and electromagnetic interference (EMI) generation. Inverter losses are further reduced by using MOS-controlled thyristors (MCTs) as the power switches in order to take advantage of their low forward voltage. A 60 kVA breadboard version of the system has been constructed, and test results which confirm its key performance characteristics are presented     

一种新型航空静止变流器的研究

 提出了一种新型的航空静止变流器方案, 采用分布式电能变换技术, 系统由规格统一、种类有限的印刷线路板构成, 没有高压功率器件, 可以克服目前静止变流器技术能量集中变换和结构复杂等缺点。变流器由4 个推挽正激变换器和4 级级联逆变器组成。分析了系统的工作原理和控制方案。研制的原理样机验证了该静止变流器具有效率高、输出波形质量好、可靠性高、工程实现简便等特点。     

A multioutput LLC-type parallel resonant converter

When an LLC-type parallel resonant converter (LLC-PRC) operates above resonant frequency, the switching transistors can be turned off at zero voltage. Further study reveals that the LLC-PRC possesses the advantage of lower converter voltage gain as compared with the conventional PRC. Based on the analytic results derived, a complete set of design curves from which a systematic design procedure is developed is obtained. Experimental results from a 150-W, 150-kHz, multioutput LLC-type PRC power supply are presented     

Improved Mapham's inverter for HF space power conversion

An improved Mapham's inverter for high-frequency space power conversion is presented. The proposed inverter system uses a starting commutator to facilitate the starting of the conventional inverter under full-load conditions. The load conditions which cause the starting commutation failure of a conventional Mapham inverter are established. An improved inverter system to overcome the starting failure is presented and analyzed. The behavior of the improved inverter has been simulated to verify the predicted performance at start-up. A steady-state analysis of the inverter is presented, and the performance characteristics are derived     

A fixed frequency LCL-Type series resonant converter

A fixed frequency LCL-type series resonant converter (SRC) which uses an inductive output filter is proposed. Steady-state analysis of the converter is presented using complex ac circuit analysis. Based on the analysis, a simple design procedure is given. Detailed space integrated control experiment (SPICE) simulation results are presented to evaluate the performance of the designed converter under varying load and supply voltage conditions. Also, detailed experimental results obtained from a metal-oxide-semiconductor field-effect transistor (MOSFET) based 500 W converter are presented to verify the analysis and SPICE simulation results. The results obtained from the analysis, SPICE simulation and the experimental converter are compared. The proposed converter requires a narrow variation in pulsewidth while maintaining lagging power factor mode of operation for a very wide variation in the load as well as supply voltage     

A New Resonant Mode Amplifier Produces Clean AC Power

A new resonant mode power amplifier design is described which has a number of advantages over the power amplifiers available today. In particular, it has low or no EMI because of the nature of its operation. The new amplifier design is based upon a resonant mode dc-dc converter used in a push-pull configuration. All the advantages of the resonant mode power converters, such as high efficiency, small size and weight, excellent dynamic performance, low or no EMI (compared to PWM switch mode power converter), etc., are present in this new design.     

A Large-Signal Dynamic Simulation for the Series Resonant Converter

A simple nonlinear discrete-time dynamic model for the series resonant dc-dc converter is derived using approximations appropriate to most power converters. This model is useful for the dynamic simulation of a series resonant converter using only a desktop calculator. The model is compared with a laboratory converter for a large transient event.     

逆变电源输出交流电压分段式前馈控制方法研究

为解决水泵三相AC 660 V电机在DC 750~1 250 V下的供电及起动问题,通过开展电机驱动系统设计研究,形成了以两电平主电路结构、电压空间矢量脉冲宽度调制技术和电压/频率恒定控制策略为基础的水泵电机逆变变频控制方案。在方案中针对较宽输入直流电压范围下的输出交流电压控制技术进行了攻关并取得了突破,形成了相应关键技术解决方案。通过水泵负载试验,全面验证了该方案的有效性和可行性。     

Starter/generator employing resonant-converter-fed induction machine. II. Hardware prototype

The feasibility of operation of a new procedure to start a jet engine (JE) and to generate power by means of a single induction machine (IM) directly coupled to the turbine has been shown by means of a hardware prototype. An introduction, background, operation principle of this type of a system and software simulation portion was presented in Part I. Both in software simulation and in the experimental phase of the studies the JE is replaced by a DC machine. The DC machine is brought to an initial speed by the motoring operation of the IM. Later, the IM is taken into generating mode and the DC machine is into motoring mode of operation. This mode would correspond to the turbine catch-up initiation phase and initiate driving phase of the induction generator in the actual world. The generated power is then converted to a three-phase, 400 Hz (in software), 60 Hz (in hardware), 115 V voltage-regulated bus via a double stage power conversion utilizing a 20 kHz parallel resonant high frequency AC link and pulse density modulated converter technology. Independent of the coupled machine speed, a constant amplitude and constant frequency three-phase voltage-regulated AC bus is formed and maintained by the proper control of the power converters.     

Development of a driver board power supply for high power IGBTsused in three-phase inverters

High power IGBTs have been widely used for medium power inverters up to 200 kVA. Their driver circuits often require multiple-output, isolated power supplies. This paper presents a simple flyback power supply especially designed for the driver boards of three-phase IGBT inverters. The detailed circuit diagrams and typical waveforms are reported. Certain performance data are given. The power supplies have been used in 100 kVA inverters for an electric vehicle drive and for a wind turbine inverter     

Single-stage converters for PV lighting systems with MPPT andenergy backup

Single-stage converters (SSCs) are proposed for applications of photovoltaic powered lighting system (PPLS). The synchronous switch technique is employed to develop the SSCs which can fulfill maximum power point tracking (MPPT), battery charging, discharging, and lamp ballasting features. Several typical SSCs are discussed. One of the proposed SSCs, which is the integration of a buck-boost charger/discharger and a class-D series resonant parallel loaded inverter, is analyzed and designed into a PPLS. Both pulsewidth modulation (PWM) and variable-frequency controls are used to govern the system operation. The controller is implemented on a single-chip microprocessor. Simulated and experimental results of the proposed system for driving up to sixteen GE TBX 26 W fluorescent lamps are used to verify the theoretical prediction and feasibility. The proposed system has a simple configuration, as well as a zero voltage switching (ZVS) feature, and can achieve the same functions as those in conventional systems when abrupt insolation changes do not occur frequently. These result in the inherent merits of lower cost, more compact size and possibly achieving higher reliability over conventional systems     

State-plane analysis of zero-voltage-switching resonant DC/DCconverters

The state-plane analysis technique is established for the zero-voltage-switching resonant DC/DC power converter family of topologies, namely the buck, boost, buck-boost, Cuk, sepic, and dual-sepic converters. The state plane provides a compression of information, which allows the designer to examine the nonlinear dynamics of resonant converter operation. Utilizing the state plane, modes of resonant converter operation are examined. Expressions are derived for the switching frequencies at the boundaries between these modes and at the boundary of energy conversion     

开关点预置三相四线SPWM逆变器研究

脉宽调制型交直交变速恒频电源采用开关点预置SPWM逆变器,该逆变器由三相桥,交流滤波器,中点形成变压器及控制、驱动电路组成。绝缘栅双极性晶体管是一种新型的电力电子器件;应用该器件为功率器件,研制了一套15kVA开关点预置SPWM逆变器。由于对电路各个部分均进行了充分分析和优化设计,实际制作的逆变器具有较小的体积、重量,并具有优越的电性能。