Linearized large signal modeling, analysis, and control design of phase-controlled series-parallel resonant converters using state feedback

This paper proposes a linearized large signal state-space model for the fixed-frequency phase-controlled series-parallel resonant converter. The proposed model utilizes state feedback of the output filter inductor current to perform linearization. The model combines multiple-frequency and average state-space modeling techniques to generate an aggregate model with dc state variables that are relatively easier to control and slower than the fast resonant tank dynamics. The main objective of the linearized model is to provide a linear representation of the converter behavior under large signal variation which is suitable for faster simulation and large signal estimation/calculation of the converter state variables. The model also provides insight into converter dynamics as well as a simplified reduced order transfer function for PI closed-loop design. Experimental and simulation results from a detailed switched converter model are compared with the proposed state-space model output to verify its accuracy and robustness

Cyclic-averaging for high-speed analysis of resonant converters

Abstract—The paper describes the development and application of a cyclic-averaging technique for the rapid analysis of high-order resonant power converters. To provide a focus to the paper, particular emphasis is given to a 3rd-order LCC voltage output converter topology. The proposed methodology predicts steady-state voltages and currents throughout the circuit, and provides estimates of the stresses on the resonant circuit components. State-space simulations and experimental results from a 350 V-input/150 V-output converter are used to demonstrate a prediction accuracy comparable with time-domain integration-based techniques is achievable, while requiring only 1/10,000th of the computation time. In addition, a comparison with Spice simulation results shows that cyclic averaging provides commensurate predictions of voltage and current stresses on the resonant circuit components. Issues arising from the stray capacitance associated with the resonant inductor, and the corresponding sensitivity of the predicted output voltage, are also considered

Discussion of the technology and research in fuel injectors common rail system

Common rail is one of the most important components in a diesel and gasoline direct injection system. It features a high-pressure (100 bar) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors. Third-generation common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up to 2,500 bar. The purpose of this review paper is to investigate the technology and research in fuel injectors common rail system. This review paper focuses on component of common rail injection system, pioneer of common rail injection, characteristics of common rail injection system, method to reduce smoke and NOx emission simultaneously and impact of common rail injection system. Based on our research, it can be concluded that common rail injection gives many benefit such as good for the engine performance, safe to use, and for to reduce the emission of the vehicle. Fuel injection common rail system is the modern technology that must be developed. Nowadays, our earth is polluting by vehicle output such as smoke. If the common rail system is developed, it can reduce the pollution and keep our atmosphere clean and safe

Observer based feedback control of 3rd order LCC resonant converters

The paper considers specific issues related to the design and realisation of observer-based feedback of isolated output voltage for resonant power converters. To provide a focus to the study, a 3rd order LCC converter is employed as a candidate topology. It is shown that whilst resonant converters nominally operate at high switching frequencies to facilitate the use of small reactive components, by appropriate pre-conditioning of non-isolated resonant-tank voltages and currents, the resulting observer can be implemented at relatively low sampling frequencies, and hence, take advantage of low-cost digital hardware. Experimental results are used to demonstrate the accuracy of observer estimates under both transient and steady-state operating conditions, and to show operation of the observer as part of a closed-loop feedback system where the LCC resonant converter is used as a regulated power supply

Analysis and design of a modular multilevel converter with trapezoidal modulation for medium and high voltage DC-DC transformers

Conventional dual active bridge topologies provide galvanic isolation and soft-switching over a reasonable operating range without dedicated resonant circuits. However, scaling the two-level dual active bridge to higher dc voltage levels is impeded by several challenges among which the high dv/dt stress on the coupling transformer insulation. Gating and thermal characteristics of series switch arrays add to the limitations. To avoid the use of standard bulky modular multilevel bridges, this paper analyzes an alternative modulation technique where staircase approximated trapezoidal voltage waveforms are produced; thus alleviating developed dv/dt stresses. Modular design is realized by the utilization of half-bridge chopper cells. Therefore, the analyzed converter is a modular multi-level converter operated in a new mode with no common-mode dc arm currents as well as reduced capacitor size, hence reduced cell footprint. Suitable switching patterns are developed and various design and operation aspects are studied. Soft switching characteristics will be shown to be comparable to those of the two-level dual active bridge. Experimental results from a scaled test rig validate the presented concept

One-Quadrant Switched-Mode Power Converters

This article presents the main topics related to one-quadrant power converters. The basic topologies are analysed and a simple methodology to obtain the steady-state output-input voltage ratio is set out. A short discussion of different methods to control one-quadrant power converters is presented. Some of the reported derived topologies of one-quadrant power converters are also considered. Some topics related to one-quadrant power converters such as synchronous rectification, hard and soft commutation, and interleaved converters are discussed. Finally, a brief introduction to resonant converters is given.Comment: 25 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

Modelling and regulation of dual-output LCLC resonant converters

The analysis, design and control of 4th-order LCLC voltage-output series-parallel resonant converters (SPRCs) for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are employed and new analysis techniques are developed to establish operating mode boundaries with which to describe the internal behaviour of a dual-output resonant converter topology. The designer is guided through the most important criteria for realising a satisfactory converter, and the impact of parameter choices on performance is explored. Predictions from the resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control

Switched Capacitor Voltage Converter

This project supports IoT development by reducing the power con- sumption and physical footprint of voltage converters. Our switched- capacitor IC design steps down an input of 1:0 - 1:4 V to 0:6 V for a decade of load current from 5 - 50A

Analysis and control of dual-output LCLC resonant converters with significant leakage inductance

The analysis, design and control of fourth-order LCLC voltage-output series-parallel resonant converters for the provision of multiple regulated outputs, is described. Specifically, state-variable concepts are developed to establish operating mode boundaries with which to describe the internal behavior and the impact of output leakage inductance. The resulting models are compared with those obtained from SPICE simulations and measurements from a prototype power supply under closed loop control to verify the analysis, modeling, and control predictions

Self-oscillating control methods for the LCC current-output resonant converter

Abstract—A strategy for self-oscillating control of LCC current-output resonant converters, is presented, based on varying the phase-angle between the fundamental of the input voltage and current. Unlike other commonly employed control methodologies,the proposed technique is shown to provide a convenient, linear system input-output characteristic suitable for the design of regulators. The method is shown to have a similar effect as controlling the dc-link supply voltage, in terms of output-voltage/current control. The LCC converter variant is used as an application focus for demonstrating the presented techniques, with simulation and experimental measurements from a prototype converter being used to show the practical benefits. Third-order small and large-signal models are developed, and employed in the formulation of robust output-voltage and output-current control schemes. However, notably, the presented techniques are ultimately generic and readily applicable to other resonant converter variants